† oˈnologyObs.rare—0. [f.Gr. ὄνο-ς ass + -λογία speech: prob.repr. a mod.L. *onologia.] Foolish talking; braying. 1674Blount Glossogr. (ed. 4), Onology, vain babling, talking like an Ass.1678Phillips (ed. 4) List Barbarous Words, Onologie, a talking like an Ass.