costliest See {costly} costly adj 1: entailing great loss or sacrifice; "a dearly-won victory" [syn: {dearly-won}] 2: having a high price; "costly jewelry"; "high-priced merchandise"; "much too dear for my pocketbook"; "a pricey restaurant" [syn: {dear(p)}, {high-priced}, {pricey}, {pricy}] [also: {costliest}, {costlier}]