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Definition of costly

costly

/ˈkɔːst.li/
cost · ly
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costly Lexical Profile

costly Game Scores & Validity

• adjective

1

Costing a great deal of money; high in price or financial expense.

Example

"Replacing the historic building's roof proved to be a costly undertaking for the municipality."

2

Resulting in severe loss, damage, sacrifice, or negative consequences.

Example

"A single costly error in the final minutes of the match cost the team the championship."

Synonyms
View all synonyms for costly
Antonyms
View all antonyms for costly

Word Nuance & Usage

Although "costly" ends in "-ly", it functions exclusively as an adjective (forming the comparative "costlier" and superlative "costliest") and is not used as an adverb in standard modern English.

• Rhymes for costly

• Nearby Words

costing
costless
costliness
costly
costume
costumer
costumey

Word Origin & Etymology

From Middle English "costli", formed from the noun "cost" (borrowed from Old French "cost", ultimately from Latin "constare", meaning "to stand at" or "to cost") plus the adjectival suffix "-ly".

Cite this Entry

Wordmom. (2026). Definition of Costly. In Wordmom Dictionary. Retrieved Nov 5, 2026, from https://wordmom.com/dictionary/costly
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