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

• big-ticket
• dear
• expensive
• extravagant
• high
• high-end
• high-ticket
• precious
• premium
• priceless
• pricey
• pricy
• spendy [chiefly Northwest]
• ultraexpensive
• 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

However, the plan does not address several costly tax cuts proposed by President Trump in his 2024 campaign, including tax-free tips, overtime, and Social Security benefits. —Howard Gleckman, Forbes.com, 12 May 2025

Not a lot went right in the Twins’ first 22 games, a run that was marked by costly errors — many by their pitchers — and an offense that had yet to hit its stride. —Betsy Helfand, Twin Cities, 11 May 2025

Labor can be less costly, engineering can be more precise and construction can be faster. —Sam Lubell, Los Angeles Times, 9 May 2025

At less than $100, this is a small fraction of the cost of other automatic litter boxes and can help to know when problems begin, rather than a costly and stressful vet visit. —Molly Higgins, Wired News, 9 May 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