The Collaborative International Dictionary
Amphicoelian
Amphicoelian \Am`phi*c[oe]"li*an\, Amphicoelous \Am`phi*c[oe]"lous\, a. [Gr. ? hollowed all round; 'amfi` + ? hollow.] (Zo["o]l.) Having both ends concave; biconcave; -- said of vertebr[ae].
Wiktionary
amphicoelian
a. amphicoelous