a. Phys. [f. Gr. ἀμφί on both sides + κοῖλ-ος hollow + -OUS.] Concave on both sides, double concave. Applied to vertebræ, as in the backbone of a fish.
1869. Huxley, in Jrnl. Geol. S., XXVI. 33. Amphicœlous centra.
1879. Le Conte, Elem. Geol., 470. Their vertebræ were amphicœlous or biconcave, as in fishes and many extinct reptiles.
