凹陷 Traditional form: 凹陷 Pinyin (reading): āoxiàn Definitions: to cave in; hollow; sunken; depressed Characters: 凹 - concave, hollow; depressed; pass, valley 陷 - to sink, to plunge; trap, pitfall Traditional characters: 凹 - concave, hollow; depressed; pass, valley 陷 - to sink, to plunge; trap, pitfall