cost·ly 
/ˈkɑ:stli/ adjective
cost·li·er; cost·li·est /ˈkɑ:stli/ adjective [also more costly; most costly] 1 : having a high price : costing a lot : expensive
▪ costly jewelry ▪ We use less costly materials in our products. ▪ It was too costly to fix her car after the accident, so she decided to buy a new car instead. 2 : causing people to lose something or to suffer
▪ They won the game, but their best player was injured, so it was a costly victory. ▪ The decision to wait could be a costly mistake.
▪ costly jewelry ▪ We use less costly materials in our products. ▪ It was too costly to fix her car after the accident, so she decided to buy a new car instead.
▪ They won the game, but their best player was injured, so it was a costly victory. ▪ The decision to wait could be a costly mistake.
— cost·li·ness noun [noncount]
