gullywasher means an intense, but usually short-lived, rainstorm. Lexicurio rates it Sui generis — a strength score of 91 out of 100.
Why “gullywasher” is a great word
GULLYWASHER — [Noun] An intense, but usually short-lived, rainstorm. From 'gully' (a water-worn ravine) + 'washer' (one that washes), first attested c. 1903. Unlike a 'drizzle,' which is a light, steady seepage, or a 'deluge,' which suggests a prolonged, catastrophic flood, a gullywasher is a brief, localized fury. It is the percussive roar on a tin roof that drowns out all conversation, the instant transformation of a dirt lane into a churning brown river, and the abrupt, sun-drenched silence that follows, leaving the air smelling of ozone and wet earth—a violent but fleeting ceremony of purification for the land.
Etymology
From gully + washer. First use appears c. 1903.
noun
- An intense, but usually short-lived, rainstorm.“"Then maybe some preacher got a tad too zealous on Sunday" Thinking of his " frog-strangler," Lucy said, "In Montana, we'd call this a gullywasher." " Gullywasher. I like that." She could hear him, up there on the island in Thomas Jefferson's ...”