Chit
late 18th century: Anglo-Indian, from Hindi ciṭṭhī ‘note, pass’.
wiktionary
From Middle English chitte(“a young animal, cub, whelp”), from Old English *ċytten, *ċietten, *ċitten, from Proto-West Germanic *kittīn, from Proto-Germanic *kittīną(“young animal, fawn, kid”). Cognate with Scots chit(“chit”), Low German kitte(“young animal”), German Kitz(“fawn, kid”). See also kid.
From Middle English *chit, *chitte, from Old English ċīþ(“germ, seed, sprout, shoot”), from Proto-Germanic *kīþą(“sprout”), from Proto-Indo-European *ĝī-, *ĝey-(“to divide, part, split open, sprout”). Cognate with Middle Dutch kiede(“sprout”), dialectal German Keid(“sprout”). Doublet of scion.
From chitty, from Hindi चिट्ठी(ciṭṭhī, “letter, note, written message”).
Perhaps from specialized technical use of Etymology 2, above, “a bud; an excressence” (Hunter 1882).
Euphemistic variation of shit.
etymonline
chit (n.1)
"a short letter, note," 1776, short for chitty (1690s), from Mahrati (Hindi) chitthi "letter, note, memorandum," from Sanskrit chitra-s "distinctively marked" (see cheetah).
chit (n.2)
"small child," 1620s, originally "young of an animal" (late 14c.), of uncertain origin; perhaps a playful deformation of kitten, but The Middle English Compendium compares Old High German kizzin "kid" and Century Dictionary mentions Old English cið "a shoot, sprout, sprig."
