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
Related Words
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.
They tend to concentrate capital in the largest stocks whereas small caps typically attract specialist or active fund managers and, therefore, have a habit of being more cyclical and risk sensitive.
From MarketWatch • May 5, 2026
"Different types of plastics behave differently during conversion, and additives such as dyes and stabilisers can interfere with the process. Efficient sorting and pre-treatment are therefore essential to maximise performance and product quality."
From Science Daily • May 4, 2026
“There aren’t easy answers — ‘Jack has a bad father, therefore Jack is bad’ — because Simon also has a troubled relationship with his father,” Thorne says.
From Los Angeles Times • May 4, 2026
"When it comes to defence industry cooperation, Japan is by no means a country with the world's most advanced weaponry; therefore, we must actively work to build relationships with other nations," Sato told AFP.
From Barron's • May 3, 2026
It's useful, therefore, to be familiar with the terms commonly used to describe each element.
From "Understanding Basic Music Theory" by Catherine Schmidt-Jones and Russel Jones
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.
