adj
costly
KOST-lee
adj
1
Expensive, or requiring a heavy price to be paid.
"Repairing the roof turned out to be a costly job."
"It was a costly mistake that nearly ended the company."
How to Use Costly
Learner’s notesIn plain EnglishExpensive in money, or damaging in some other serious way, like a "costly error."
Common pairings
costly mistake
a costly delay
costly repairs
Word Forms
costlier comparative, more costly comparative, costliest superlative, most costly superlative
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Repairing the roof turned out to be a _____ job.
Etymology
From Middle English costly, formed from cost plus -ly.