Green’s Dictionary of Slang

1. (US, also mashup) drunk.

1882		Harvard Crimson 23 Jan. 🌐 She asks me how I’d say that I was – well, I was ‘mashed’ unless I used slang. Why, I’d a good deal rather say ‘I’m perfectly gone;’ that isn’t slang, and it means just the same.
1883		E.J. Milliken Childe Chappie’s Pilgrimage 27: Coarse-tongued, canaille, apt at smirk and wink, / Would keep him meshed and ‘mashed’ on desperation’s brink.
1933		‘William Juniper’ True Drunkard’s Delight.
1957		(con. 1943) A. Myrer Big War 125: Highball me, son, I’m mashed in a gin-sling: I’m jiggered, sir.
1968		A. Salkey Late Emancipation of Jerry Stover (1982) 117: You’ lookin’ real mash’ up.
1998		A. Warner Sopranos 119: Shopping when you’re mashed is dangerous, ye find yourself wearing weird colours.
1999		Guardian 12 Oct. 43/1: There are hundreds of words for drunk [...] ‘wazzed,’ ‘mashup,’ ‘ratted’.
2000		Guardian Editor 4 Feb. 10: I don’t go out and get mashed every night.
2012		J. Fagan Panopticon (2013) 157: I’d just had shite news [...] I just needed tae get mashed.
2021		P Howard Braywatch 181: [H]alf of us were still half mashed from the night before.

2. ruined, destroyed.

1882		Eve. Bull. 23 June 3/2: My Muvver Hubbard bonnet is all mashed.
2009		J. Joso Soothing Music for Stray Cats 125: I found this poncy dressing gown thing, I figured I had to borrow something, my gear was mashed.

3. emotionally overcome.

1887

Bowyer & Royle [perf. G.H. Mac Dermott] ‘Down went the Captain’ 🎵 For such a fatal beauty she'd unfortunately got / A All those who chanced to look at Kate were mashed upon the spot.

4. drugged.

1976

P. Theroux Family Arsenal 172: The villains step on their toes – their paws, like. That one’s probably been mashed.

5. (drugs) under the influence of a recreational drug.

1997		N. Barlay Curvy Lovebox 24: Being mashed don’t help.
2005		B. Hare Urban Grimshaw 64: I got mashed because I liked to.
2009		Metro (London) 26 June 5: Mashed on opium wallabies are the real p`erpetrators [...] The ‘out-of-control’ marsupials get ‘high as a kite’.