Green’s Dictionary of Slang

birthday suit n.

also birthday, birthday coat, ...finery, bodysuit
[the state in which one emerges from the womb; note also a probable pun by Rochester in cit. c.1673 – in which a ‘birthday coat’ is properly a coat worn at court on occasion of a royal birthday]

the naked body.

[[UK]Rochester ‘A Ramble in St James’s Park’ in Works (1999) 77: So he not only eats, and talks, [...] Nay looks, and lives, and loves by Rote / In an old tawdrey Birth-Day-Coat].
[UK]Cleland Memoirs of a Woman of Pleasure (1985) 122: The figure I made, which my friend gallantly protested, infinitely outshone all other birth-day finery.
[UK]Smollett Humphrey Clinker (1925) II 111: I went in the morning to a private place, along with the housemaid, and we bathed in our birth-day soot.
[UK]Grose Classical Dict. of the Vulgar Tongue ms. additions n.p.: Birthday Suit. I saw him dres’d in his Birthday suit. i.e. Stark Naked.
[UK]Grose Classical Dict. of the Vulgar Tongue n.p.: birth day suit. He was in his birth-day suit, that is, stark naked.
[UK]Lancaster Gaz. 16 Feb. 3/1: Two men, for a small wager, ran from Skerton to Bolton [...] one of them in his birth-day suit.
[UK]B.H. Malkin (trans.) Adventures of Gil Blas (1822) I 50: I will strip this holy father to his birth-day suit.
[UK]Lex. Balatronicum.
[UK]R.B. Peake Haunted Inn II iii: I’ll go to gaol in my birth-day suit.
[UK]Swell’s Night Guide 113/2: Birthday suit, stark naked, in buff, Adamized.
[UK]Leics. Mercury 19 Aug. 3/4: Jackson [...] with two black eyes, and having torn up his clothes, must have appeared in his ‘birth-day suit’.
[US]Matsell Vocabulum.
[US]R.F. Burton City of the Saints 74: Their only dress, when they were not in ‘birth-day suit,’ was the Indian languti.
[UK]B.M. Carew Life and Adventures.
[US]Breckenridge News (Cloveport, KY) 23 Aug. 3/3: My mother was so poor that half the time I had no clothes but my ‘birthday suit’.
[UK]H. King Savage London 193: ‘That there birthday suit o’ yourn won’t do ashore, youngster,’ remarked Jerry, with a grim smile. [...] What was it to be naked as long as he was comfortable?
[Aus]Crowe Aus. Sl. Dict. 8: Birthday Suit, in his skin.
[UK]Gem 16 Mar. 1: Even if Oi was to turn up at roll-call in me little birthday suit.
[UK]Western Mail 10 Jan. 10/3: His Birthday Suit [...] The man went out of his mind, and ran about the High-street [...] without a vestige of clothing.
[US]T. Thursday ‘Hail the Professor’ in Top-Notch 1 Sept. 🌐 My kid show top caved in [...] causing six of my freaks to crawl from under, minus everything but their birthdays.
[US]Wood & Goddard Dict. Amer. Sl.
[Ire]Wexford Conservative 31 Oct. 4/1: An eccentric character [...] appeared naked. [...] ‘Thunder,’ said he, ’why I am in a Birth-day Suit’.
[US]A. Halper Foundry 95: I wonder how Max’l looks in his birthday suit?
[US]W. Winchell On Broadway 29 Apr. [synd. col.] The stripteaser [...] sat there being interviewed (in her birthday clothes).
[UK]D. Bolster Roll On My Twelve 23: Old Blackie in ’is birthday suit ’oppin’ around like a dancing Dervish.
[US]W.R. Burnett Little Men, Big World 201: ‘Some of them painted fairly realistic nudes to sell. I posed for a lot of them.’ ‘In your birthday suit?’.
[UK]N. Dunn Up the Junction 22: ‘Are yer going to wear yer pink pyjamas?’ ‘No, me birthday suit.’.
[Ire](con. 1930s–40s) N. Conway Bloods 106: ‘The Bull’ standing all alone in the glory of his birthday suit.
[Oth]D. Marechera House of Hunger (2013) [ebook] There’s homeless people out there. There’s many going about in the rags of their birthday suit.
[UK]P. Theroux Picture Palace 258: You want a life study – the original birthday suit? Sorry, I’m in retirement. No pictures.
[UK]M. Amis London Fields 419: Our babies are born, not in their birthday suits, but in uniform.
[UK]Guardian G2 3 Dec. 18: He’s wearing his altogether, his birthday suit.
[US]G. Pelecanos Night Gardener 216: I think they wear g-strings [...] Technically, they’re not in their birthday suits.
[UK]R. Antoni Carnival 139: They suddenly caught sight of Eddoes in his bodysuit: ‘Oui papa-yo! But the man naked! Toe-tee and all ringing in the breeze’.
M. Wilkerson ‘A Clean White Sun’ in ThugLit Sept./Oct. [ebook] Big Stud Blood’s in his birthday suit.
[US](con. 1991-94) W. Boyle City of Margins 139: ‘You’re gonna go say thanks, huh? Maybe show up in your birthday suit?’.