Green’s Dictionary of Slang

great adj.3

SE in slang uses

In compounds

great divide, the (n.) [pun on the Great Divide, in the Blue Mountains, or the US equivalent in the Rocky Mountains, cited in the celebrated poem ‘Eskimo Nell’]

1. the vagina.

[UK] ‘Eskimo Nell’ in ‘Count P. Vicarion’ Bawdy Ballads XIV: She shed her garments one by one [...] Till at last she stood in her womanhood, and they saw the great divide.
[US]Maledicta IV:2 (Winter) 185: The Great Divide (occurs in the well-known poem ‘Eskimo Nell.’ It also refers to the cleavage [an Australian use from the mountain range], especially a neckline of the Biblical type – Lo and behold – when her dumplings are boiling over).

2. (Aus.) the cleavage between a woman’s breasts.

see sense 1.
great gas (n.) (also good gas) [gas n.1 (3)]

(Irish) something, or someone, extremely enjoyable.

[Ire]‘Flann O’Brien’ At Swim-Two-Birds 79: It was good gas all right.
[Ire]‘Myles na gCopaleen’ Best of Myles (1968) 48: It would be great gas to prove the brother wrong for once.
[Ire]J.P. Donleavy Ginger Man (1958) 175: He’s good gas.
[Ire](con. 1940s) B. Behan Borstal Boy 198: Someone was imitating my accent, and getting great gas out of it.
[UK]L. Dunne Goodbye to The Hill (1966) 16: It was great gas, with me imagining that I was Roy Rogers on Trigger, galloping after the outlaws.
[Ire]H. Leonard Da (1981) Act I: Your old fellow is great gas.
[Ire](con. 1930s) L. Redmond Emerald Square 298: The Barn was great gas then, there was always something going on.
[Ire]R. Doyle Snapper 149: He was dying to go and watch a bit of the American Wrestling [...] it was great gas.
[Ire]D. Healy Sudden Times 142: Oh dearie, dearie me, he said, but you’re great gas.
C. Toibin Brooklyn (2015) 36: ‘It’s great gas. You’d enjoy it’.
great house (n.) [the size of the building in comparison with the original homes of its inmates]

the workhouse.

[UK](con. 1840s–50s) H. Mayhew London Labour and London Poor I 394/1: ‘But anything’s better than the house. I’ll live on 4d. a day, and pay rent and all, and starve half my time, rather nor the great house’ (Union).

In phrases

Great White Way (n.)

see separate entry.