spate vs onrush

spate and onrush both are nouns.

Word	Noun	Adjective	Verb	Adverb
spate	Yes	No	No	No
onrush	Yes	No	No	No

As nouns, onrush is a hyponym of spate; that is, onrush is a word with a more specific, narrower meaning than spate:

Other hyponyms of spate include debris storm, debris surge.

spate (noun)	onrush (noun)
the occurrence of a water flow resulting from sudden rain or melting snow	(military) an offensive against an enemy (using weapons)
a sudden forceful flow	a forceful forward rush or flow
(often followed by `of') a large number or amount or extent