Green’s Dictionary of Slang

farting adj.

[fart v. (1) + sfx -ing]

a general pej., piffling, trivial, irrelevant.

[US]H. Miller Tropic of Cancer (1963) 312: The British, in their usual fumbling farting way, had kept us on pins and needles.
[US]B. Malamud Tenants (1972) 37: Fartn Jew slumlord.
[US]R. Coover Public Burning (1979) 245: Is Richard Nixon a Farting Quacker who dreamt of selling his pajamas at Coney Island?
[UK]K. Sampson Powder 7: So Sensira did a couple of farting little one-off gigs with the Grams.
[UK]K. Sampson Outlaws (ms.) 129: None of them farting tin efforts where the tea leaks all over the fucking table the moment you pour.

SE in slang uses

In compounds

farting-crackers (n.) [cracker n.1 (1)]

(UK Und.) breeches, trousers.

[UK]B.E. Dict. Canting Crew n.p.: Farting-crackers c. Breeches.
[UK]New Canting Dict. [as cit. c.1698].
[UK]Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
[UK]Grose Classical Dict. of the Vulgar Tongue.
[UK]Lex. Balatronicum.
[UK]Egan Grose’s Classical Dict. of the Vulgar Tongue.
[UK]Roger’s Profanisaurus 3 in Viz 98 Oct. 13: farting crackers n. Trousers ‘When invited to a Black Tie function, the correct mode of attire for gentlemen would be – white dress shirt and collar, cummerbund, black shoes, black dinner jacket and corresponding farting crackers’, (from ‘Dubreft’s Guide to Etiquette’, by Buckridge Pottinger).
[UK]P. Baker Fabulosa 292/1: farting crackers trousers.
farting strings (n.) (also puckering string)

a fig. part of the body, which can be damaged by some form of excess, usu. laughter, e.g. If you don’t stop that, I’ll bust my farting strings!

[US] ‘Word-List From West Brattleboro’ in DN III:vi 454: puckering-string, n. To ‘break one’s puckering string’ means to lose control of one’s self and burst into hysterical giggling.
[Ire]Joyce Ulysses 302: Couldn’t loosen her farting strings but old cod’s eye was waltzing around her showing her how to do it.
[UK]Roger’s Profanisaurus in Viz 87 Dec. n.p.: farting strings n. An imagined part of the body which can be damaged by over exertion through laughter. e.g ‘Hey! Stop it will ya, before I bust me farting strings’.
posting at 12 Apr. 🌐 A.A. Milne must have snapped his farting strings laughing at all these kids reading about the exploits of Pooh.
farting-trap (n.)

(Anglo-Irish) a light two-wheeled vehicle carrying four people, seated two on each side, back to back.

[UK]Farmer & Henley Sl. and Its Analogues.