/ Dictionary / Index O onkus: Meaning and Definition of Find definitions for: on•kus Pronunciation: (ong'kus), [key] — adj. Australian Slang. unpleasant, unattractive, or unacceptable; bad. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Onkelos onlap 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