Green’s Dictionary of Slang

1. (orig. RN) a popular toast before drinking; cite 2023 prefaces taking LSD.

1877		J. Habberton Some Folks 51: ‘So here’s to “the capen’s mark, a dead sure thing.” Bottoms up.’ The glasses were emptied in silence, and turned bottoms uppermost on the bar.
1896		LeHigh Burr 16-17 24: Here's to Charlie’s perennial youth, bottoms up!
a.1906		Verses from Harvard Advocate: 3rd Ser. 1886-1906 108: You know how we are wont to stand / And hold on high the brimming cup, / And how the leader gives command, / And how we drink to ‘Bottoms up!’.
1918		J.M. Grider War Birds (1926) 102: We started doing bottoms up in rotation. It was a riot.
1921		N.Y. Tribune 18 Dec. 53/5: Rall [...] raising his glass, performed an archaic ceremony once known as ‘bottoms up’.
1929		J. Tully Shanty Irish 291: He lifted his glass – All followed him [...] Many voices chanted – ‘Bottoms up for Old Hughie’.
1932		‘R. Scully’ Scarlet Pansy 195: Fay poured out a stiff one for each of the men and suggested bottoms up, and then another and another.
1947		F. Brown Fabulous Clipjoint (1949) 69: Bottoms up, Gardie.
1952		K.C. Lamott Stockade 16: ‘Bottoms up,’ Kaneshiro said, raising his cup.
1960		N. Hilliard Maori Girl 111: Come on, get it down, folks [...] Bottoms up!
1964		L. Nkosi Rhythm of Violence II iii: Politicians are anti-Life. Me? I say bottoms up both to women and to glasses!
1975		D. Nobbs Fall and Rise of Reginald Perrin (1976) 113: ‘Bottoms up, Ponsonby,’ he said.
1992		K. Lette Llama Parlour 98: ‘What is it?’ ‘A Leg-Opener,’ he said simply. ‘Bottoms up.’.
2000		C. Cook Robbers (2001) 58: Him pouring scotch in two glasses, clink clink, bottoms up.
2017		T. Spicer Good Girl Stripped Bare 44: Hey, it’s Friday, bottoms up!
2023		F. Bill Back to the Dirt 122: Miles reached beneath the wrap, pulled on one of the corners, two squares [of LSD] stuck to his finger, he placed them on his tongue. ‘Bottoms up’.

2. (US prison) in rhy. sl., a cup.

1960

(con. 1950-1960) R.A. Freeman Dict. Inmate Sl. (Walla Walla, WA) 16: Bottoms up – a cup.