Green’s Dictionary of Slang

1. to disgust someone, to shock someone; thus excl. gross me out! that really disgusts me!

1965		Wisconsin State Jrnl 17 Jan. 1-2: If the person is completely obnoxious, he would find himself ‘grossing out’.
1972		D. Jenkins Semi-Tough 45: Bubba got caught by his date, Honey Jean Lester, while he was beating off [...] Shake imitated Honey Jean Lester [...] ‘Bubba Littleton! You done grossed me out for the last time’.
1977		C. McFadden Serial 71: Your socks [...] smell outrageous. I mean, they’re really grossing me out.
1989		M. Amis London Fields 207: Thelonius eats nothing but fruit: even a string-bean, even a radish, would gross him out.
1998		D. Clowes Ghost World 72: He once poured tons of ketchup on his hot dog and it grossed me out!
2002		(con. 1980s) i80s.com 🌐 gross out/grotesque To make someone sick.
2009		T. Black Gutted 70: Camera close-ups on the actual knife wounds [...] I pushed the folder aside, said, ‘Are you trying to gross me out?’.
2010		L. Redhead Thrill City [ebook] Being grossed out is the least of your worries after shitting a watermelon.
2022		J. Hannaham Didn’t Nobody Give a Shit 15: [S]he thought her case grossed out the [parole] panel.

2. to be overwhelmed by disgust.

1981

J. Wambaugh Glitter Dome (1982) 227: I almost grossed out. I never take a trick a second time if he makes me watch kiddy porn.