Lewis Short
vertĭcŭla | vertĭcŭlus, i | vertĭcŭlum, i (noun F.m.n) : dim.verto
* A joint, = vertebra, Lucil. ap. Non. p. 207, 24; cf. Fest. p. 371.—In machines, Vitr. 10, 13, 1.— Called also , , , Sol. 4; Cael. Aur. Tard. 4, 3, 242; , , , id. Acut. 3, 17, 138.
Charlton T. Lewis, Charles Short, A Latin Dictionary