costly

1 of 2

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

costliness

2 of 2

noun

cost·​li·​ness

ˈkȯs(t)-lē-nəs also ˈkäs(t)-

plural -es

: the quality or state of being costly : high price or value : expensiveness

Synonyms of costly

Adjective

• expensive
• valuable

Examples of costly in a Sentence

Adjective

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

Adjective

Former Homeland Security Secretary Kristi Noem had been ridiculed by lawmakers for a costly $220 million ad featuring her on horseback warning against immigrating to the United States illegally. — Molly Parks, The Washington Examiner, 24 Sep. 2026

Including bird protection from the start of the design process also removes the need to install costly collision-preventing retrofits post-construction. — Chicago Tribune, 24 Sep. 2026

That’s not to mention the extremely complicated and likely costly process of maintaining these servers. — Victor Tangermann, Futurism, 24 Sep. 2026

Earlier this month, Silver Diner filed a lawsuit against Fraport, claiming that the company breached its 2022 contract with the restaurant by enforcing costly renovations at an significantly higher price than initially agreed. — Angel Saunders, PEOPLE, 24 Sep. 2026

Word History

First Known Use

Adjective

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