Lewis Short
(verb) : hŏrĭor, hori, and hŏrĭtor, āri, prim. forms of hortor, from the root ΟΡΩ, whence ὄρνυμι, ὁρμή, ὁρμάω, etc.
* To urge, incite, encourage: hortatur quod vulgo dicimus, veteres nonnulli horitur dixerunt, ut Ennius libro XVI. (29): prandere jubet horiturque. Idem in X. (28): horitatur induperator,Diom. p. 378 P. (Ann. v. 409 and 350 Vahl.).
Charlton T. Lewis, Charles Short, A Latin Dictionary