bi·con·cave /(ˌ)baɪ(ˌ)kɑnˈkev, ˈkɑnˌ/
  (a.)兩面凹的
  bi·con·cave /ˌbaɪ(ˌ)kɑnˈkev, (ˈ)baɪˈkɑnˌ/ 形容詞
  雙凹形的,雙凹面的
  Bi·con·cave a.  Concave on both sides; as, biconcave vertebræ.
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  biconcave
       adj : concave on both sides [syn: concavo-concave]