useful
Americanadjective
-
being of use or service; serving some purpose; advantageous, helpful, or of good effect.
a useful member of society.
- Synonyms:
- beneficial, efficacious, profitable
- Antonyms:
- useless
-
of practical use, as for doing work; producing material results; supplying common needs.
the useful arts; useful work.
- Synonyms:
- beneficial, efficacious, profitable
- Antonyms:
- useless
adjective
-
able to be used advantageously, beneficially, or for several purposes; helpful or serviceable
-
informal commendable or capable
a useful term's work
noun
Other Word Forms
- unuseful adjective
- unusefully adverb
- unusefulness noun
- usefully adverb
- usefulness noun
Etymology
Origin of useful
Explanation
If you can use something, it's useful. Useful things are handy for whatever you're doing. If something is just what you need or you just find it helpful, then it's useful. A hammer is useful in building many things. Coasters are useful if you don't want a coffee table to get stains. College degrees are useful — or necessary — for many careers. MacGyver would tell you that just about anything can be useful at some point: it all depends what you need to do.
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.
The team points out that systems based on atomic clocks, which rely on very precise optical transitions, could be especially useful.
From Science Daily • Apr. 10, 2026
There is a third type of IRA that is especially useful for high earners.
From MarketWatch • Apr. 9, 2026
And for dogs that aren't particularly active, TV can be useful she says.
From BBC • Apr. 9, 2026
Such a contention may be useful for our own personal life-narratives.
From The Wall Street Journal • Apr. 8, 2026
Honestly, the only way this power would be useful is if it got me to Arizona sooner.
From "Clairboyance" by Kristiana Kahakauwila
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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.