Possibly related to squirt (“small child”); from 19th c.
Meanings
(countable, derogatory, informal) A person of low status.
Not a favourite son, of course — Lord, no! — more a sort of illegitimate backstairs sort of sprog, you know: a sort of spotty squit that nobody really likes. 1989, Richard Curtis, Ben Elton, Blackadder Goes Forth (episode "Goodbyeee")
I couldn't believe my ears: at Roedean a new girl spent at least a term having it drummed into her what an insignificant little squit she was; and here were these girls being welcoming! 2007, Katharine Whitehorn, Selective Memory, unnumbered page:
'It isn't so funny when it's the other way round, is it?' I snarl, before adding, 'You geeky little squit,' for good measure. 2000, Josie Lloyd, Emlyn Rees, Come Again, page 153:
(Norfolk, uncountable) Nonsense; amusing stories.
In 1985, asked by the writer Richard Whittington-Egan if he believed in this apparition, an old local man replied that it was ‘a load of old squit.’ 2009, Alison Weir, The Lady In The Tower: The Fall of Anne Boleyn, page 420:
'Cor blast, Tovell, you don't half talk some squit at times!' exclaimed Ted Carter.
‘Squit! It's the gospel truth.[…]’ 2007, Ann Neve, Ride Upon the Storm, page 162:
(Internet, transitive) To disconnect (an IRC server) from a network.
[…] these problems solved themselves atfter^([sic]) some 10 minutes or so, without an ircop interferring^([sic]) into channel affairs by squitting his/her server to gain chanop status. 1994, Bernhard Lorenz, “ChanOp for Irc Opers”, in alt.irc (Usenet):
Today, I was awakened by a call from one of my IRC ops, telling me that my net had been 'taken over'. An ircop had squitted all the servers, and had a script that kept them disconnected from the net. 1996, Jesse, “A warning to all irc users”, in alt.irc (Usenet):
(onomatopoeic) A light squishing or splattering sound.
She turned away and stalked back through the lounge, her running shoes making a squit-squit-squit sound on the tiles, punctuated by the slam of the front door. 2021, Malcolm Devlin, Unexpected Places to Fall From, Unexpected Places to Land:
"Mr. Kuttner, you know I'm the best in this business, don't you?" he said, swatting at a mosquito.
It went squit and left a smear of blood on his cheek. 2007, S. M. Stirling, The Sunrise Lands, page 79: