'Costly' definitions:

Definition of 'costly'

From: WordNet
adjective
Entailing great loss or sacrifice; "a dearly-won victory" [syn: dearly-won, costly]
adjective
Having a high price; "costly jewelry"; "high-priced merchandise"; "much too dear for my pocketbook"; "a pricey restaurant" [syn: costly, dear(p), high-priced, pricey, pricy]

Definition of 'Costly'

From: GCIDE
  • Costly \Cost"ly\ (k?st"l?; 115), a. [From Cost expense.] [1913 Webster]
  • 1. Of great cost; expensive; dear. [1913 Webster]
  • He had fitted up his palace in the most costly and sumptuous style, for the accomodation of the princess. --Prescott. [1913 Webster]
  • 2. Gorgeous; sumptuous. [Poetic.] [1913 Webster]
  • To show how costly summer was at hand. --Shak. [1913 Webster]