中央凹陷,凹洼,凹状
Concavity \Con*cav"i*ty\, n.; pl. {Concavities}. [L. concavitas: cf. F. concavit['e]. See {Concave}.] A concave surface, or the space bounded by it; the state of being concave.
concavity n 1: a shape that curves or bends inward [syn: {concave shape}, {incurvation}, {incurvature}] 2: the property possessed by a concave shape [syn: {concaveness}]