[kawst-lee, kost-]

adjective, cost·li·er, cost·li·est.

costing much; expensive; high in price: a costly emerald bracelet; costly medical care.
resulting in great expense: The upkeep of such a large house is costly.
resulting in great detriment: It was a costly mistake because no one ever trusted him again.
of great value; very valuable; sumptuous.
lavish; extravagant.

Origin of costly

First recorded in 1350–1400, costly is from the Middle English word costli. See cost, -ly
Related formscost·li·ness, nouno·ver·cost·li·ness, nouno·ver·cost·ly, adjectiveun·cost·ly, adjective

Synonyms for costly Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for costly

Contemporary Examples of costly

Historical Examples of costly

  • She was plain; she was simple; but it was the costly simplicity of extravagance.

    Her Father's Daughter

    Gene Stratton-Porter

  • I have studied the sex in a very celebrated and costly school.

    In the Valley

    Harold Frederic

  • A fine and costly residence, particularly that of a great official.

  • Hn-lfing, name of a costly sword, which Finn presents to Hengest, 1144.



  • But we have costly presents for those who are friendly towards us.'


    Theodor Hertzka

British Dictionary definitions for costly


adjective -lier or -liest

of great price or value; expensive
entailing great loss or sacrificea costly victory
splendid; lavish
Derived Formscostliness, noun
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

Word Origin and History for costly

late 14c., from cost + -ly (1). Earlier formation with the same sense were costful (mid-13c.), costious (mid-14c.).

Online Etymology Dictionary, © 2010 Douglas Harper