spate

Short definition from Wiktionary

Noun

1. 1
   A (sudden) flood or inundation of water; specifically, a flood in or overflow of a river or other watercourse due to heavy rain or melting snow; (uncountable, archaic) flooding, inundation.
2. 2
   A sudden heavy downpour of rain.
3. 3
   A sudden increase or rush of something; a flood, an outburst, an outpouring.

Verb

1. 1
   To (suddenly) flood or inundate (a river or other watercourse) with water.
2. 2
   To (suddenly) rain heavily; to pour.