costly

Definitions

cost (← con- + stāre, 'to stand at a price') + -ly = 'standing at a high price' → expensive, or, on the figurative line of cost, exacting a heavy toll.

Why It Means This

Although costly can mean plainly 'expensive,' it leans toward the figurative side of cost — the price of harm, not just money. A costly mistake or a costly victory stresses that something painful was paid, not merely that a sum was large. That toll-of-suffering flavor is what separates it from expensive.

Common Collocations

• 1.a costly mistake代价高昂的错误
• 2.costly error代价高的失误
• 3.prove costly代价沉重
• 4.costly delay代价高昂的延误

Example Sentences

• 1.

  Repairing the old roof turned out to be very costly.

• 2.

  The error was a costly mistake that lost them the contract.

• 3.

  It was a costly victory — they won, but lost their best players.

Easily Confused

costly vs expensive — both mean 'high in price,' but expensive is the neutral price word (an expensive watch), while costly often carries the figurative weight of cost — the price in harm or loss (a costly mistake, a costly war). You'd say an expensive restaurant, not a costly one; but a costly error, not usually an expensive error.