scat

From Middle English scet, schat, from Old English sċeatt (“property, goods”) and Old Norse skattr (“wealth, treaure”); both from Proto-Germanic *skattaz (“cattle, kine, wealth”), from Proto-Indo-European *skatn-, *skat- (“to jump, skip, splash out”).

Cognate with Scots scat (“tax, levy, charge, payment, bribe”), West Frisian skat (“treasure, darling”), Dutch schat (“treasure, hoard, darling, sweetheart”), German Schatz (“treasure, hoard, wealth, store, darling, sweetheart”), Swedish skatt (“treasure, tax, duty”), Icelandic skattur (“tax, tribute”), Latin scateō (“gush, team, bubble forth, abound”).

Origin uncertain. Both the Oxford English Dictionary and Merriam-Webster suggest derivation from Ancient Greek σκῶρ (skôr, “excrement”), compare English scato-, but Random House Dictionary suggests that the popular character of the word makes this unlikely. Perhaps from English dialectal scat (“to scatter, fling, bespatter”), or an alteration of shit

Uncertain. The OED, which connects the senses "blow" and "shower" only tentatively, suggests that at least the former might be onomatopoeia. Dialectally, the word can also refer to "a spell" of any kind of weather, e.g. "a scat of fine weather", "a scat of frost".

1920s, probably imitative.

Mid 19th century:

perhaps an abbreviation of scatter.

perhaps representing a hiss followed by the word cat. Compare Swedish schas (“shoo, begone”).

Alternatively, from the expression quicker than scat (“in a great hurry”),

Possibly from scoot, from the root of shoot.

From the taxonomic name of the family.