Green’s Dictionary of Slang

filthy adj.

[synon. dirty adj. (9)]

1. (US Und.) in possession of incriminating items, esp. drugs.

[US]C. Cooper Jr Scene (1996) 162: FBI, Tubbs. You’re under arrest [...] I bet you’re filthy, Tubbs.

2. (US campus) amazing, excellent [on bad = good model].

[Aus]K. Lette Girls’ Night Out (1995) 188: ‘Filthy waves,’ agreed Bodge. ‘Classic.’.
[Aus]T. Winton Lockie Leonard, Legend (1998) 17: Have you heard Storytime yet? Filthy good band.
Online Sl. Dict. 🌐 filthy adj 1. very good, excellent; COOL, AWESOME. (‘Those shoes are filthy!’).
[Aus]Sun-Herald (Sydney) 18 Jan. 29: The talent was filthy, the babes were lush and the mosh pit was going off.

3. (Aus.) sarcastic, ill-tempered.

[Aus]R.G. Barrett Mud Crab Boogie (2013) [ebook] I was filthy on your giving me local anaesthetic.
[Aus]N. Cummins Tales of the Honey Badger [ebook] Needless to say, I was filthy. I told her I was already full anyhow and didn’t want them [i.e. stolen sweets].

4. (Aus.) sexy.

[US]D. Jenkins Semi-Tough 236: ‘You better be an All-Pro in the rack, son, because you done got hold of yourself a po-ran-ah fish.’ I hope filthy little Linda has worn Dreamer’s ass full out by now.
[Aus]R.G. Barrett Wind & Monkey (2013) [ebook] Les followed Digger up the stairs, his eyes burning holes in her shapely little behind as it swished slightly from side to side under her filthy mini dress.

5. (Aus. teen) unacceptable, dishonourable.

[Aus](con. 1960s-70s) T. Taylor Top Fellas 69/1: It was considered absolutely filthy to use your boots. If you fought you fought clean.

In compounds

Filthy MacNasty (n.)

a nickname for an unpleasant man, esp. a ‘peeping tom’ or ‘dirty old man’.

[US]E. Anderson Thieves Like Us (1999) 120: If I ever catch old Filthy MacNasty peepin’ [...] I’ll kick his end clear off.
filthy pillows (n.)

the female breasts.

rtw132 Maureen’s Lusty Confessions 🌐 Please, please have a bit of giblet pie, while you fondle my filthy pillows. I have desires to bump uglies with you in my dreams, and I pray that my dreams may one day become a fantastic reality... Do you feel the same way??

In phrases

filthy (on)

(Aus. Und.) furious with.

[Aus]R.G. Barrett Real Thing 21: What had the boys absolutely filthy was to think that some prick [...] was going to kill the one person [...] who the boys genuinely loved.
[Aus]Smith & Noble Neddy (1998) 145: ‘The only reason that he has agreed is because they have decided to empty him [throw him] out of the taskforce. He is filthy on them and wants to even up with them.’.
filthy with [phr. filthy rich, but note filthy, the n. (1)]

full with, over-loaded with, usu. money.

Kincaid Dispatch (KS) 1 Aug. 5/2: Empty beer bottles [...] are the source of much satisfaction to these small boys, for selling the same keeeps him filthy with pocket money.
[US]Times (Philadelphia, PA) 25 Oct. 3/2: The Republicans [...] ‘are filthy with money’ and are spending it liberally.
[US]Salt Lake Telegram (UT) 25 Jan. 4/1: ‘Why, he’s filthy wif money’.
Montogomery Advertiser (AL) 18 Nov. 4/6: ‘In a few days I’ll be perfectly filthy with money’.
E. Sterne Road of Ambition 137: Just filthy with money—that’s their trouble—and the more they have the more they want.
[US]J.P. McEvoy Showgirl 163: Dough. She must be filthy with it.
[US]J. Archibald ‘Time Will Tell’ in Phantom Detective Sept. 🌐 There’s an old guy runnin’ a pawnshop [...] He’s filthy with dough.
[US]T. Marvin ‘College for Crooks’ in Ten Detective Aces Feb. 🌐 You been taught better than to lift goods in a depot. They’re filthy with plainclothes.
R.L. Tobin Center of the World 92: Smug, self-centred, patronizing, cityfied, smooth, and probably filthy with money.
in Stanton & Banham Cambridge Paperback Guide to Theatre 245: ‘I’m filthy with money,’ he confided, flashing his gross dress-ring.
S. Oglesby Riding High 230: Don’t ya worry, I’m filthy with money. I’m the uh, what’s the word, Maxie — eccentric type, right?