costly

adjective

cost·​ly ˈkȯs(t)-lē 

costlier; costliest

1

a

: commanding a high price especially because of intrinsic worth

costly gems

b

: rich, splendid

2

: made or done at heavy expense or sacrifice

a costly mistake

costliness noun

Synonyms

• expensive
• valuable

Examples of costly in a Sentence

We use less costly materials in our products.

It was too costly to fix her car after the accident, so she decided to buy a new car instead.

They won the game, but their best player was injured, so it was a costly victory.

The decision to wait could be a costly mistake.

Recent Examples on the Web

Despite strong performances from key players like Phil Foden and Erling Haaland, City's push for a fourth straight league crown was derailed by a few costly draws late in the campaign. —Ben Verbrugge, MSNBC Newsweek, 16 Aug. 2025

Plastics Technology Readiness Matrix Preserving Social License to Operate As global awareness of environmental justice rises, companies that proactively address community siting, health impacts, and international waste flows will preserve operating licenses and avoid costly litigation. —Trond Arne Undheim, Forbes.com, 16 Aug. 2025

Both options can be costly − for example, a 2020 report from the National Disability Institute, in partnership with several universities, estimated that a household with an adult with a disability requires, on average, an additional $17,690 a year. —Madeline Mitchell, USA Today, 15 Aug. 2025

But there remains work to be done in the transfer market with manager David Moyes in the middle of a costly squad overhaul. —Patrick Boyland, New York Times, 15 Aug. 2025

Word History

First Known Use

14th century, in the meaning defined at sense 1a

Kids Definition

costly

adjective

cost·​ly ˈkȯs(t)-lē 

costlier; costliest

1

: of great cost or value

costly furs

2

: gained at great expense or sacrifice

a costly victory

costliness noun