concavity

n (a) [U] quality of being concave 凹状; 凹形. (b) [C] concave surface 凹面.

compulsory, compunction, computation, computational, compute, computer, computerization, computerization, -isation, computerize, computerize, -ise, computing, comrade, comrade-in-arms n (pl comrades-in-arms), comradely, comradeship, con, con man, concatenate, concatenation, concave, conceal, concealment, concede, conceit, conceited, conceitedly, conceivable, conceivably, conceive, concentrate, concentrate on, concentrated, concentration, concentric, concept, conception, conceptive, conceptual, concern, concerned,