/ Dictionary / Index O oleaceous: Meaning and Definition of Find definitions for: o•le•a•ceous Pronunciation: (ō"lē-ā'shus), [key] — adj. belonging to the Oleaceae, the olive family of plants. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: oleaceous (Thesaurus) olé oleaginous Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language