Green’s Dictionary of Slang

1. a prostitute.

1591		Greene Notable Discovery of Coosnage 44: If there bee anie yong gentleman that id a nouice [...] to him some common filth (that neuer knew loue) faine an ardent and honest affection, till she and her cros-biters haue verst him to the beggars estate.
1608		A Yorkshire Tragedy I v: wife: O my sweet husband! hus.: Filth, harlot.
1611		R. Cotgrave Dict. of Fr. and Eng. Tongues n.p.: Fille perdue. A desperate filth, gracelesse flurt; or ... Fille de ioye.

2. an objectionable, rude person.

1867		Cumberland Pacquet 23 Apr. 8/1: She replied, ‘Gir oot, ye nasty oald filth,’ and knocked themoney out of his hand.
1941		P.C. Wren Uniform of Glory 36: ‘You unspeakable species of filth! You walking stink!’.
1969		J. Hibberd Dimboola (2000) 79: Teach that Catholic filth a lesson, Angus.

3. (UK Und., also dirty filth) the police, esp. the CID (Criminal Investigation Department).

1968		J. Barlow Burden of Proof 41: The waiter was also an earwig and he whispered in Vic’s ear, ‘The filth is here. Table five’.
1970		G.F. Newman Sir, You Bastard 164: The filth didn’t gimme his card.
1979		K. Bonfiglioli After You with the Pistol (1991) 332: Every [...] professional team of thieves has a [...] ‘lighthouse’. [...] He has but one simple, God-given skill: he can recognize ‘fuzz’, ‘filth’, ‘Old Bill’ or any other form of copper, however plainly-clothed.
1984		B. Ellem Doing Time 189: filth: underworld slang for police.
1989		M. Amis London Fields 247: Thelonius seemed offended by Keith’s mild hint that the filth would soon put two and two together.
1999		J. Poller Reach 139: Let’s say [...] you get a whole bunch of parking tickets and get in a fix with the filth.
2000		J.J. Connolly Layer Cake 134: It’s gonna be crawling with filth.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] 68/2: filth n. 2 (also the filth or the dirty filth) any authority figure, esp. applied to police or prison officers.
2002		J. Cameron Hell on Hoe Street 117: ‘So you ain’t the filth?’ ‘No, I am not the police.’.
2006		I. Rankin Naming of the Dead (2007) 203: To Santal she was still ‘a pig’, ‘the filth’.
2010		W. Ings ‘Trolling the Beat to Working the Soob’ in Int’l Jrnl Lexicog. 23:1 69: Terms for the police found both in boobslang and on the street include Demon, headlice (po-LICE), pig and filth.
2018		C. Hammer Scrublands [ebook] ‘I’ve been over it [i.e. evidence] a thousand times with the filth’.
2018		I. Welsh Dead Man’s Trousers [39]: Then Mel’s calling the lawyer [...] Wi Hammy bein filth it’s the smart move.
2024		J. Meades Empty Wigs (t/s) 323: The filth knew they’d never make the charges stick.

4. a quality of rawness, e.g. applied to music.

1978

R. Charles Brother Ray 163: They got a certain stink that the guys in L.A. lack. [...] I miss the filth—the East Coast filth—that you hear on the streets and in the recording studios of New York City.

5. applied to a thrown ball, spin.

2020

D. Winslow ‘Broken’ in Broken 6: No filth on it, no spin, just a straight-ahead fastball across the center of the plate.