Green’s Dictionary of Slang

worthless, useless; thus occas. antonym worth a fart, worthwhile, valuable (see cit. 1772).

1540		D. Lyndsay Satyre of Thrie Estaits (1604) 65: I wil not gif for al your play worth an sowis fart.
c.1650		Le Strange Merry Passages and Jeasts No. 163 57: My Master hath sent you some Open-Arses, and sayes, if you keepe them not till they are be rotten as a Turd, they will not be worth a Fart.
1669		R. L’Estrange Fables of Poggius (1692) CCCLXVI 333: Your Promises are not worth a Fart.
1675		Head Nugae Venales 68: Her Mother had sent her worship some ripe medlars, that were as soft as Bran, but if she did not eat them quickly, they would not be worth one Fart.
1684		Rochester (attrib.) Sodom 327IV v: Letts see the late improvement of your art: / Bollocks! the Dildoes are not worth a fart.
1698		Elegy on the Death of Trade in Harleian Misc. II (1809) 292: His reply was in short, I have found better sport, And dont value her death of a f--t.
1734		C. Johnson Hist. of Highwaymen &c. 23: Your News, says the Tinker, is not worth a Fart.
1749		H. Fitzcotton (trans.) Homer’s Iliad 22: You think our help not worth a f---.
1772		Bridges Burlesque Homer (3rd edn) 21: Blast my liver, pluck, and heart, / If thou’rt a fighter worth a f--t!
1787		Burns ‘Death & Doctor Hornbook’ in Poetical Works (1871) 140: But Doctor Hornbook, wi’ his art And cursed skill, / Has made them baith no worth a f--t.
1922		Joyce Ulysses 316: The French! says the citizen. Set of dancing masters! Do you know what it is? They were never worth a roasted fart to Ireland.
1936		J.T. Farrell World I Never Made 118: What good was he? He wasn’t worth a fart in bed.
1952		J. Jones From Here to Eternity (1998) 564: We aint got a chance of a fart in a whirlwind of takin that trophy back next December.
1976		P. Theroux Family Arsenal 274: Your trust isn’t worth a fart.
1977		Maledicta 1 (Summer) 13: A person that you don’t like is often described in terms of various bodily parts or excretions: [...] He’s not worth a pisspot full of crabapples, and don’t amount to a fart in a whirlwind.
1998		DNZE 254/1: to be not worth a fart in a bottle, etc., to be of no value.
1999		G. Seal Lingo 197: Something that is not what it’s cracked up to be is something (or someone) pre- sented in a less than frank manner and so [...] not worth a fart in a hurricane (or storm or gale).