/ Dictionary / Index O onslaught: Meaning and Definition of Find definitions for: on•slaught Pronunciation: (on'slôt", ôn'-), [key] — n. an onset, assault, or attack, esp. a vigorous one. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: onslaught (Thesaurus) on-site Onslow Related Content Daily Word Quiz: feline Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language