- coneA surface of revolution formed by rotating a segment of a line around another line that intersects the first line.
- conureAny of many New World parakeets of the former genus Conurus, now reassigned to other genera in subfamily Arinae, principally Psittacara and Eupsittula.
- conodontAny of several extinct fish-like chordates having cone-like teeth.
- ossiconeEither of the horn-like protuberances on the heads of giraffes and male okapi. Some extinct species in the family bore antler-like ossicones.