costly
Americanadjective
-
costing much; expensive; high in price.
a costly emerald bracelet; costly medical care.
- Synonyms:
- high-priced, dear
-
resulting in great expense.
The upkeep of such a large house is costly.
-
resulting in great detriment.
It was a costly mistake because no one ever trusted him again.
-
of great value; very valuable; sumptuous.
-
lavish; extravagant.
adjective
-
of great price or value; expensive
-
entailing great loss or sacrifice
a costly victory
-
splendid; lavish
Related Words
See expensive.
Other Word Forms
- costliness noun
- overcostliness noun
- overcostly adjective
- uncostly adjective
Etymology
Origin of costly
First recorded in 1350–1400, costly is from the Middle English word costli. See cost, -ly
Explanation
Something that's costly is expensive. The worst kind of news you can hear from your car mechanic is that you need costly repairs. Things that cost a lot of money are costly, but you can also use the word for events that cost you other things — like time, happiness, or advantage. A soldier's costly mistake might result in someone's death, and a costly law might end up hurting the people it's meant to help.In the 13th century, costful was used instead, and both words stem from cost, which has a Latin root, constare, "to stand at," or "to cost."
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.
But IMF economists caution against these measures, which they describe as typically poorly designed and costly.
From Barron's • Apr. 14, 2026
Asking people to learn something new that goes against prior belief or intuition is costly.
From The Wall Street Journal • Apr. 14, 2026
Quiet professionals understand that violence is risky and costly, and use it only as a last resort.
From Slate • Apr. 13, 2026
Lawyers for police officers reported numerous calls from clients worried their personnel and medical records were exposed, raising the prospect of more costly litigation.
From Los Angeles Times • Apr. 10, 2026
Since the supercollider debacle particle physicists have set their sights a little lower, but even comparatively modest projects can be quite breathtakingly costly when compared with, well, almost anything.
From "A Short History of Nearly Everything" by Bill Bryson
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.
