[ kawst-lee, kost- ]
See synonyms for: costlycostliercostliestcostliness on

adjective,cost·li·er, cost·li·est.
  1. costing much; expensive; high in price: a costly emerald bracelet; costly medical care.

  2. resulting in great expense: The upkeep of such a large house is costly.

  1. resulting in great detriment: It was a costly mistake because no one ever trusted him again.

  2. of great value; very valuable; sumptuous.

  3. lavish; extravagant.

Origin of costly

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

synonym study For costly

1. See expensive.

Other words for costly

Other words from costly

  • cost·li·ness, noun
  • o·ver·cost·li·ness, noun
  • o·ver·cost·ly, adjective
  • un·cost·ly, adjective

Words Nearby costly Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use costly in a sentence

British Dictionary definitions for costly


/ (ˈkɒstlɪ) /

adjective-lier or -liest
  1. of great price or value; expensive

  2. entailing great loss or sacrifice: a costly victory

  1. splendid; lavish

Derived forms of costly

  • costliness, 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