concavity
n. 中央凹陷；凹洼；凹状
名词复数：concavities
近义词：depression，valley，cup，pan，well，incurvation，incurvature，concaveness，
英英释义
Noun
- a shape that curves or bends inward
- the property possessed by a concave shape
例句
用作名词(n.)
- And there also was a concavity in his car's front wing (fender).而且，他的前挡板上还凹陷了好大一块撞痕。