'onrush' definitions:

Definition of 'onrush'

From: WordNet
noun
(military) an offensive against an enemy (using weapons); "the attack began at dawn" [syn: attack, onslaught, onset, onrush]
noun
A forceful forward rush or flow; "from the bow she stared at the mesmerising onrush of the sea where it split and foamed"; "the explosion interrupted the wild onrush of her thoughts"

Synonyms of 'onrush'

From: Moby Thesaurus