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Synonyms

costly

American  
[kawst-lee, kost-] / ˈkɔst li, ˈkɒst- /

adjective

costlier, costliest
  1. costing much; expensive; high in price.

    a costly emerald bracelet; costly medical care.

    Synonyms:
    high-priced, dear
  2. resulting in great expense.

    The upkeep of such a large house is costly.

  3. resulting in great detriment.

    It was a costly mistake because no one ever trusted him again.

  4. of great value; very valuable; sumptuous.

  5. lavish; extravagant.


costly British  
/ ˈkɒstlɪ /

adjective

  1. of great price or value; expensive

  2. entailing great loss or sacrifice

    a costly victory

  3. splendid; lavish

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Related Words

See expensive.

Other Word Forms

Etymology

Origin of costly

First recorded in 1350–1400, costly is from the Middle English word costli. See cost, -ly

Explanation

Something that's costly is expensive. The worst kind of news you can hear from your car mechanic is that you need costly repairs. Things that cost a lot of money are costly, but you can also use the word for events that cost you other things — like time, happiness, or advantage. A soldier's costly mistake might result in someone's death, and a costly law might end up hurting the people it's meant to help.In the 13th century, costful was used instead, and both words stem from cost, which has a Latin root, constare, "to stand at," or "to cost."

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

But just as the extravaganza is set to kick off, many New Jerseyans are viewing their hosting duties less as an honor and more as a costly burden they could do without.

From The Wall Street Journal • May 17, 2026

Utilities must borrow money to build costly infrastructure, but then have to wait for regulators to allow them to recoup that investment.

From Barron's • May 15, 2026

Until now, manufacturers have relied heavily on costly trial-and-error testing to search for better combinations.

From Science Daily • May 13, 2026

Longer journeys use additional fuel, making it more costly and time-consuming for those involved in the sale of the ships' cargo.

From BBC • May 12, 2026

Moon material would be used wherever possible, because the moon’s lower gravity would make the trip less costly.

From "Flying to the Moon: An Astronaut's Story" by Michael Collins

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