concavo-concave (a.)兩凹的,兩面凹窪的
con·ca·vo-concave /kɑnˌke(ˌ)vo-/ 形容詞
Con·ca·vo-con·cave a. Concave or hollow on both sides; double concave. ◄ ►
concavo-concave adj : concave on both sides [syn: biconcave]