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
Synonym Usage
See expensive.
Other Word Forms
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.
Transport infrastructure across Europe, North America and central Asia must adapt to more adverse climate conditions, the United Nations said on Tuesday, warning that inaction could prove more costly than upgrades.
From Barron's • Jun. 30, 2026
I’m looking for space elevators that would eliminate the costly process of missile launch to move people and material into Earth orbit.
From The Wall Street Journal • Jun. 29, 2026
The natural option, a blue-green microalgae called spirulina, proved to be too costly and thick in consistency, causing factory equipment to clog during candy production.
From Salon • Jun. 29, 2026
The attacking full-back had started half of their league and Champions League games but became the fall guy for the team's costly defensive lapses in both competitions.
From BBC • Jun. 27, 2026
Territorial empires are tightly controlled but costly to maintain; hegemonic empires are inexpensive to maintain, because the original local rulers incur the costs of administration, but the loose tie between master and vassal encourages rebellion.
From "1491" by Charles C. Mann
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.
