[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 costlier

Contemporary Examples of costlier

  • As Bilmes reports, the Iraq and Afghanistan wars are at least 25 percent  costlier than previous projections.

    The Daily Beast logo
    How the Wars Are Sinking the Economy

    Linda Bilmes

    October 27, 2010

  • And on Friday, an Iowa ethanol producer said that the spill proves that oil production has become “costlier and riskier.”

    The Daily Beast logo
    The Next Spill Victim: Your Car

    Robert Bryce

    May 9, 2010

Historical Examples of costlier

  • Costly costumes they would exchange for costumes that were costlier.

    The Paliser case

    Edgar Saltus

  • The costlier the offerings, the better would the feast be enjoyed.

    A Tour of the Missions

    Augustus Hopkins Strong

  • Such a criticism applies only to the rarer and costlier desiderata.

    The Book-Collector

    William Carew Hazlitt

  • Indeed that reserved for Madame was much the costlier of the two.

    Joyce's Investments

    Fannie E. Newberry

  • Certainly it will be costlier than the greatest war that has ever devastated the world.

British Dictionary definitions for costlier


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 costlier



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