a. Zool. [mod. f. L. ad to, at + rostr-um beak, mouth + -AL 1.] Pertaining to or situated at the beak or snout.
1878. Bell, trans. Gegenbauer’s Comp. Anat., 457. The presence of special cartilages (rostral and adrostral) in front of the primordial cranium of the larvæ of Anura.
