The closest synonyms of thereby are “by doing so,” “in this way,” “by that means,” and “thus.” “Thereby” means “by that means.” It introduces a result that comes directly from the action just mentioned. “Therefore” and “hence” are looser matches, because they signal a logical conclusion rather than the means. Use the words below by checking whether your sentence describes how a result happened or why a conclusion follows.
Quick Answer: Best Synonyms for Thereby
Top Synonyms at a Glance
| Synonym | Fits when… | Example |
|---|---|---|
| by doing so / in doing so | The result comes from the action you just named | She trimmed the budget. By doing so, she freed up funds for training. |
| in this way / by that means | You want a plain, direct replacement | He automated the report, in this way saving hours each week. |
| thus | You want a short, formal option before an -ing verb | The team cut waste, thus improving margins. |
| as a result | The result matters more than the method | The road flooded. As a result, the school closed. |
| hence / therefore / consequently | You are stating a conclusion, not a method | The test failed; therefore, we delayed the launch. |
Correct: The company reduced packaging, thereby lowering shipping costs.
Incorrect: The company reduced packaging, thereby the shipping costs are lower.
Which One Should You Pick?
Ask one question: does the second part explain how something happened or why a conclusion follows? If it explains how, choose “by doing so,” “in this way,” or “thus.” If it explains why, choose “therefore,” “hence,” or “consequently.”
What Does “Thereby” Mean?
Definition and Part of Speech
“Thereby” is an adverb. Merriam-Webster defines it as “by that” or “by that means.” In practice, it links an action to the result it produces. Collins describes it as a formal way to introduce an important result or consequence of what you just mentioned.
Merriam-Webster lists a second, older sense: “connected with or with reference to that.” You will mostly see it in the idiom covered later in this article.
“Thereby” has no plural, tense, or comparative forms. It never changes.
Pronunciation and Syllables
“Thereby” has two syllables: there-by. Britannica’s audio page for the U.S. pronunciation encodes the sound as /ðeɚˈbaɪ/, with the stress on the second syllable. Britannica hosts native-speaker audio for the word.
Merriam-Webster’s respelling is “ther-BY.” It also lists a variant with the stress on the first syllable. Both are recorded, so neither counts as an error. The “th” is the voiced sound, as in “this.”
Word Origin
Dictionary.com traces “thereby” to Middle English therby and Old English thǣrbī, a combination of “there” and “by.” Merriam-Webster dates its first known use to before the 12th century. The OED also places its earliest use in the Old English period.
How to Use Thereby in a Sentence
The Basic Pattern: Action, Then Result
Most sentences with “thereby” follow the same pattern: action + comma + thereby + result.
- The city widened the bike lanes, thereby encouraging more people to commute by bike.
- She back-dated the form, thereby invalidating it.
The action comes first. “Thereby” then points back to it and names what it caused.
Why Thereby Is Usually Followed by an -ing Verb
“Thereby” is most often followed by an -ing phrase, as in “thereby reducing costs.” This keeps the result attached to the main action without starting a new sentence. It is not a strict rule. Merriam-Webster’s own kids’ entry shows a past-tense verb after it: “thereby lost her chance to win.”
If you follow “thereby” with a full clause that has its own subject and verb, the sentence usually goes wrong. See the mistakes section below.
Do You Need a Comma Before Thereby?
A comma before “thereby” is the usual choice when it introduces a result after a complete main clause. Linguaholic explains that the comma marks off the effect of an action mentioned earlier in the sentence. The comma is a matter of convention and readability, not a hard rule. When “thereby” sits inside a clause, no comma is needed.
- With comma: He revised the plan, thereby avoiding a delay.
- Without comma (inside the clause): The change would thereby avoid a delay.
For formal or published work, check your style guide.
Is Thereby Formal?
Yes. Collins labels it formal, and it appears most often in academic, legal, business, and journalistic writing. In casual speech, people more often say “so” or “which meant” instead.
Synonyms for Thereby, Grouped by Meaning and Tone
Thesauruses list many words for “thereby.” WordHippo, for example, lists consequently, accordingly, thus, ergo, then, therefore, thereupon, thusly, and hence. Not all of them work as replacements. The groups below sort them by how well they fit.
Closest Single-Word Synonyms
- Thus: Works in nearly the same slot. “The bridge was closed, thus forcing drivers onto the highway.”
- Hereby / therewith: Rare and legal in tone. Use them only where the setting demands it.
Formal and Academic Alternatives
- Consequently: “Sales fell in March. Consequently, the team changed its strategy.”
- Accordingly: “The rules changed, and the company adjusted accordingly.”
- Hence: “The data were incomplete; hence, the results are preliminary.”
These state a conclusion. They do not describe the means, so they usually need a new sentence or a semicolon.
Phrase Alternatives
Phrases are often the safest swaps because they keep the original meaning.
- By doing so / in doing so: “She renegotiated the contract. By doing so, she cut costs.”
- In this way / in that way: “He shared the notes early, in this way giving everyone time to prepare.”
- By that means / through this: “The lab filtered the water, and by that means removed the contaminants.”
- As a result: “The server crashed. As a result, orders were lost.”
Casual Alternatives
- So: “We moved the meeting, so everyone could attend.”
- Which: “She fixed the bug, which stopped the crashes.”
These sound natural in email and conversation, and they work in most workplace writing.
Thereby vs. Similar Words
These words overlap, but they are not interchangeable everywhere.
| Word | Core meaning | Grammar | Swap for “thereby”? |
|---|---|---|---|
| thereby | by that means | Adverb; usually before an -ing phrase | n/a |
| therefore | for that reason | Adverb; links two statements | Rarely |
| thus | in this way; as a result | Adverb; flexible position | Often |
| hence | for this reason; from now | Adverb; often opens a conclusion | Rarely |
| whereby | by which | Relative adverb; links to a noun before it | No |
Thereby vs. Therefore
“Thereby” tells you how a result happened. “Therefore” tells you why a conclusion follows.
- Thereby: She signed the form, thereby accepting the terms.
- Therefore: She read the terms and agreed; therefore, she signed.
Writers on usage often use a quick test. “How?” points to “thereby,” and “why?” points to “therefore.” A university-hosted guide that cites Garner’s Modern American Usage draws the same line.
Thereby vs. Thus
The two overlap most. “Thus” is shorter and more flexible, and it can also mean “in this manner” or “so far.” “Thereby” always points back to an action or condition.
- Thus: The tests were repeated, thus confirming the finding.
- Thereby: The tests were repeated, thereby confirming the finding.
Here they are interchangeable. You cannot swap them in phrases like “thus far.”
Thereby vs. Hence
“Hence” usually opens a conclusion and can also refer to time (“a year hence”). It does not describe a means. Swapping it for “thereby” often forces a rewrite.
Thereby vs. Whereby
“Whereby” means “by which” and follows a noun that names a method or system. “Thereby” follows an action.
- Whereby: The city adopted a system whereby residents vote online.
- Thereby: The city let residents vote online, thereby raising turnout.
Which Synonym to Use in Academic, Business, Legal, and Everyday Writing
- Academic writing: “Thereby” and “thus” are both standard. Use “consequently” or “hence” when you are stating a conclusion, not a mechanism.
- Business writing: Prefer plain phrases: “by doing so,” “as a result,” or a “which” clause. They read faster in reports and emails.
- Legal and technical writing: “Thereby” appears in formal documents, and its exact meaning matters. Keep it when precision is needed, and avoid swapping in “therefore,” which changes the logic.
- Everyday writing: “So” and “which” are usually enough. “Thereby” can sound stiff in a text or chat.
Example Sentences with Thereby
Everyday: He set two alarms, thereby making sure he would wake up.
Academic: The study added a control group, thereby reducing the risk of bias.
Workplace: We shortened the onboarding checklist, thereby helping new hires start faster.
Formal or legal: The tenant signed the lease, thereby agreeing to its terms.
Technical: The script caches results locally, thereby cutting load time.
Inside a clause (no comma): By sharing the draft, she would thereby invite feedback.
Is There an Opposite of Thereby?
No true antonym exists. “Thereby” is a connecting word that expresses a link between an action and its result. It has no direct opposite in the way “hot” has “cold.”
Some sites list words like “independently,” but that is a stretch. If you need contrast, you can express the idea with phrases such as “despite this,” “regardless,” or “without this effect.” These change the logic of the sentence and are not opposites in the dictionary sense.
“And Thereby Hangs a Tale”: Meaning of the Idiom
“And thereby hangs a tale” means “there is a story behind that.” Dictionary.com notes it comes from Shakespeare and is a humorous way to signal that a long explanation is coming. Here “thereby” carries the older sense of “connected with that.”
Example: “She never eats at that restaurant, and thereby hangs a tale.”
Thereby Crossword Clue: Answers by Letter Count
Crossword answers depend on the clue’s exact wording and the number of squares.
- 4 letters: THUS. The Crossword Solver site lists it as the shortest solution for “thereby.” For clues like “___ facto, thereby,” the answer is IPSO. Crossword Solver reports IPSO as the likely answer for that clue.
- 4 letters (fill-in): INSO, for the clue “___ doing: thereby.” Crossword Solver gives INSO as the likely answer.
- 9 letters: IPSOFACTO. This is the most likely answer for “thereby” in a Times Cryptic clue, according to Crossword Solver.
Always confirm with the crossing letters. Solver sites are based on past puzzles, so a new clue may differ.
Common Mistakes with Thereby and Its Synonyms
Swapping Synonyms Without Checking the Meaning
Incorrect: The team missed the deadline, thereupon the client complained.
Correct: The team missed the deadline, and the client complained soon afterward.
Why: “Thereupon” means “immediately after that,” not “by that means.” Thesauruses list it near “thereby,” but it does not mean the same thing.
Using Thereby When No Result Follows
Incorrect: She opened the window, thereby it was Tuesday.
Correct: She opened the window, thereby letting in fresh air.
Why: “Thereby” needs a result that comes from the action.
Leaving Out the Comma or the -ing Form
Incorrect: He resigned thereby he lost his pension.
Correct: He resigned, thereby losing his pension.
Why: After a complete clause, use a comma and, usually, an -ing phrase.
Confusing Thereby with Therefore
Incorrect: The rain was heavy, thereby we stayed home.
Correct: The rain was heavy; therefore, we stayed home.
Why: “Therefore” states a conclusion. “Thereby” describes the means of a result, and it cannot open a new clause with its own subject.
Easy Ways to Remember Thereby
This is a learning aid, not a grammar rule.
- Split the word: there + by = “by that.” Ask yourself, “By what means?”
- Use the how/why test: “how” points to thereby, and “why” points to therefore.
- Picture the pattern: action, comma, thereby, -ing result.
Practice Exercise: Choose the Right Word
Fill-in-the-Blank Questions
- The city banned cars downtown, ___ cutting traffic noise.
(a) whereby (b) thereby (c) thereupon - He skipped the final review, ___ missing the error.
(a) thereby (b) hence (c) therefore - Which sentence is correct?
(a) He saved the file, thereby he protected the data.
(b) He saved the file thereby protected.
(c) He saved the file, thereby protecting the data. - Which word can replace “thereby” in “The firm cut costs, thereby raising profits”?
(a) whereby (b) thus (c) thereupon - The evidence was clear; ___, the board approved the plan.
(a) thereby (b) whereby (c) therefore - True or false: “Thereby” has a plural form.
- What part of speech is “thereby”?
(a) conjunction (b) adverb (c) preposition
Answers and Explanations
- (b) thereby. It links the ban to its result. “Whereby” needs a noun before it.
- (a) thereby. The missed error is the means-based result of skipping the review.
- (c). A comma plus an -ing phrase is the standard pattern.
- (b) thus. It fits the same slot and keeps the meaning.
- (c) therefore. The second half is a logical conclusion.
- False. It is an adverb and does not change form.
- (b) adverb.
Frequently Asked Questions
What is another word for thereby?
“Thus” is the closest single word. Phrases such as “by doing so,” “in this way,” and “by that means” also work well. Words like “therefore” and “hence” fit only when you are stating a conclusion.
What does thereby mean in simple words?
It means “by that means” or “as a result of that.” It points back to an action and names what that action caused.
What is the difference between thereby and therefore?
“Thereby” explains how a result happens, and “therefore” explains why a conclusion follows. They are not usually interchangeable.
Can I use “thus” instead of “thereby”?
Often, yes, especially before an -ing verb. “Thus” also has other meanings, such as “so far,” which “thereby” lacks.
Do you put a comma before thereby?
Usually, yes, when “thereby” introduces a result after a full clause. No comma is needed when it sits inside the clause.
Can a sentence start with thereby?
It is uncommon and can sound archaic. Dictionaries show it mainly in the middle of sentences. Starting with “By doing so” is clearer.
Is thereby a formal word?
Yes. It suits academic, legal, and professional writing, and many people prefer “so” or “which” in casual writing.
Is thereby a conjunction or an adverb?
It is an adverb. Some writers use it to connect ideas the way a conjunction does, but dictionaries classify it as an adverb.
What is the opposite of thereby?
There is no true antonym. You can show contrast with phrases like “despite this,” but these are not opposites in the dictionary sense.
How do you pronounce thereby?
It has two syllables. U.S. sources show the stress on the second syllable, roughly “ther-BY,” and Merriam-Webster also lists a first-syllable-stress variant.
What does “and thereby hangs a tale” mean?
It means there is a story behind what was just mentioned. The line comes from Shakespeare.
What is the difference between thereby and whereby?
“Thereby” follows an action. “Whereby” follows a noun and means “by which.”
What is a 4-letter crossword answer for thereby?
THUS is common. Clues that include “___ facto” usually want IPSO, and “___ doing” clues often want INSO.
Choosing the Right Word for Thereby
The closest synonyms of thereby are “by doing so,” “in this way,” and “thus.” Use them when you are describing how a result happened. Use “therefore,” “hence,” or “consequently” when you are stating a conclusion. To check yourself, ask “how?” or “why?” and pick the word that answers it. In short: action, comma, thereby, result.
