Green’s Dictionary of Slang

1. thin beer; thus any thin, tasteless drink, alcoholic or otherwise; cite 1876 only denotes a mixed drink, not a weak one.

1876		St Louis Globe-Democrat 19 Jan. n.p.: They nominate ‘bottled electricity,’ ‘lemonade with a stick in it,’ ‘jig-water,’ ‘budge,’ ‘bilge-water,’ ‘bug-juice,’ ‘rat-poison,’ ‘fusel-oil,’ ‘red-eye,’ ‘liquid ointment,’ ‘cut nails,’ ‘hard head,’ ‘benzine,’ ‘nitro-glycerine,’ ‘oil,’ ‘tea,’ ‘eye-water,’ ‘chain- lightning.’ [...] they all want the same article, alcohol, more or less diluted.
1879		Cincinnati Enquirer 7 Sept. 10/7: Lush, Budge, Bilge-water, Tamshack, Fire-water, Tangle-foot, Elixir, Dew-bowl, and various other terms denote whisky.
1898		H. Macfall Wooings of Jezebel Pettyfer 174: I want a drink. I want a glass o’ this blurry Jamaica bilgewater o’ your’n – neat.

2. (mainly juv.) nonsense, rubbish, piffle.

1762		Smollett Sir Launcelot Greaves II 9: An we once fall a-jawing, d’ye see, I can heave out as much bilge-water as another.
1878		G.M. Hopkins letter 13 May in Poems and Prose (1985) 178: Write no bilgewater about it.
1898		H. Macfall Wooings of Jezebel Pettyfer 379: By the living bilgewater! [...] that’s a woman.
1936		‘Josephine Tey’ Shilling for Candles 134: Everyone knew that what you wrote in a paper was just eye-wash. When it wasn’t bilge-water.
1944		P. Kendall Dict. Service Sl. n.p.: bilge water . . . bragging or nonsense.
1953		A. Buckeridge Jennings’ Diary 47: Oh, don’t talk such dehydrated bilge-water.
1957		F. Kohner Gidget (2001) 6: I always thought that Philemon Baucis stuff is just a lot of bilge water.
2006		R. Holland at Omnificent Eng. Dict. in Limerick Form 🌐 Baloney is sausage or tosh; / Just as bilgewater’s tosh or just slosh. / Tommyrot is the same: / Simply humbug so lame.

3. urine.

1922

Joyce Ulysses 593: The sailor, evidently giving it [male urinal] a wide berth, eased himself close at hand, the noise of his bilgewater some little time subsequently splashing on the ground.