Moving or flowing rapidly downward in a sudden manner (can function as adjective or present participle verb).
From 'downrush' plus '-ing' suffix. Functions as both an adjective ('downrushing water') and present participle ('the water is downrushing').
English's flexibility with '-ing' forms means one word can describe something happening ('downrushing'), describe a quality ('downrushing motion'), or even function as a noun ('the downrushing was violent')!
Complete word intelligence in one call. Free tier — 50 lookups/day.