therefore
Americanadverb
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thus; hence: used to mark an inference on the speaker's part
those people have their umbrellas up: therefore, it must be raining
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consequently; as a result
they heard the warning on the radio and therefore took another route
Synonym Usage
Therefore, wherefore, accordingly, consequently, so, then all introduce a statement resulting from, or caused by, what immediately precedes. Therefore (for this or that reason) and wherefore (for which reason) imply exactness of reasoning; they are especially used in logic, law, mathematics, etc., and in a formal style of speaking or writing. Accordingly (in conformity with the preceding) and consequently (as a result, or sequence, or effect of the preceding), although also somewhat formal, occur mainly in less technical contexts. So (because the preceding is true or this being the case) and then (since the preceding is true) are informal or conversational in tone.
Etymology
Origin of therefore
First recorded in 1125–75; Middle English ther(e)fore, variant of therfor therefor
Compare meaning
How does therefore compare to similar and commonly confused words? Explore the most common comparisons:
Explanation
The adverb therefore means as a result or consequence, or "for that reason." Cats and dogs tend to fight; therefore, keep your pets apart at night if you want to get some sleep. The adverb therefore is also used to introduce a conclusion that follows based on logic. You'll see this construction a lot in logic, math, and science, for example. Of course, sometimes the conclusions are false, as in this argument: "All fish live in water. A whale lives in water. Therefore, a whale is a fish." A whale is, in fact, a mammal. Therefore, the argument that a whale is a fish is wrong.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Many members of the coalition “cannot compete with the municipal grocery stores, and therefore, will be put out of business,” the complaint reads.
From The Wall Street Journal ● Aug. 24, 2026
Employment lawyer Libby Payne said: "It is possible to argue that the terms of the option are inherently unfair and therefore void, although the threshold for this is high and such challenges rarely succeed."
From BBC ● Aug. 24, 2026
The lawsuit goes on to say that the subsequent “Yellowstone” spinoffs “1883,” “1923,” “Marshalls” and “Dutton Ranch” are therefore also based on Salkin’s work.
From Los Angeles Times ● Aug. 23, 2026
The researchers therefore set out to determine whether particular species of gut microbes were linked to muscle strength and, if so, to investigate how those bacteria might influence muscle tissue.
From Science Daily ● Aug. 22, 2026
Dodos, as you know, are extinct; therefore, this rather gloomy phrase means that the thing being described is not merely dead.
From "The Unseen Guest" by Maryrose Wood
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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.