serraculum

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.

serrācŭlum, i, n.,

a steering-oar , rudder : πηδάλιον, clavus navis, Gloss. Philox.; Dig. 9, 2, 29, § 2 dub. (others, servaculum or feraculum).