irrationalis

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

irrătĭōnālis (inr-), e, adj. [2. in-rationalis],

without reason , irrational (postAug.): animal, Quint. 7, 3, 3; 24; Sen. Ep. 113, 17; 118, 14; 124, 23: usus, mechanical exercises, Quint. 10, 7, 11: anima, Tert. Poen. 12.—Subst.: irrătĭōnālĭa , ĭum, n. plur., things or creatures without reason : de irrationalibus, Quint. 8, 6, 13.—Adv.: irră-tĭōnālĭter , irrationally , Tert. adv. Marc. 2, 6 al.