concave

adj. 凹的

compulsorily, 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, concavity, conceal, concealment, concede, conceit, conceited, conceitedly, conceivable, conceivably, conceive, concentrate, concentrate on, concentrated, concentration, concentric, concept, conception, conceptive, conceptual, concern,