Green’s Dictionary of Slang

1. to make a mess (of), to spoil or ruin.

1908		Magnet 7 Mar. 5: He’s mucked up our half-holiday.
1910		H.G. Wells Hist. of Mr Polly (1946) 61: She mucked up my mushroom bed, the baggage!
1914		Sydney Sportsman (Surry Hills, NSW) 13 May 3/2: Well, dear Sir, I will conclude it— / We are mucked up to the brim.
1922		Joyce Ulysses 321: Gob, that puts the bloody kybosh on it if old sloppy eyes is mucking up the show.
1928		V. Palmer Passage 21: ‘I mucked up the first one,’ he admitted.
1936		W. Holtby South Riding (1988) 387: Our home’s no place for me with Peg stuck as a mule and Nat round every night mucking up kitchen till there’s no place to sit for them canoodling.
1941		K. Tennant Battlers 18: Musn’t muck the church up too much.
1947		J. Maclaren-Ross Of Love And Hunger 19: The belt breaking mucked everything up.
1958		A. Sillitoe Sat. Night and Sun. Morning 176: [He]’ll ask us not to muck things up.
1962		R. Hauser Homosexual Society 91: I wonder how many boys are mucked up by some of these in one year alone, so that they’re unfit to live one life or the other.
1973		G.V. Higgins Digger’s Game (1981) 144: You’re mucking us up.
1984		P. Barker Blow Your House Down 117: Except for a kinky few, and they only want to muck it up.
1997		C. Hiaasen Lucky You 145: That idiot Sinclair—he’s managed to muck up a perfectly splendid resignation.
2007		B. Reed ‘The Meat Axe by the Kitchen Door’ in Passing Strange (2015) 9: ‘See, everyone knows me, so I can’t muck up’’.
2012		J. Hodgkins ‘Peek-a-Boo’ in ThugLit Dec. [ebook] ‘[T]his was your deal. I didn’t want to muck it up’.

2. to fail, to go wrong.

1992

K. Lette Llama Parlour 10: Everybody gets so het up over kids who muck up.

3. (Aus.) to play the fool.

1941

Baker Popular Dict. Aus. Sl.

4. to dirty.

1922		Joyce Ulysses 160: Thick feet that woman has in the white stockings. Hope the rain mucks them up on her.
1949		‘Josphine Tey’ Brat Farrar 85: ‘[Y]ou don’t want that dazzling outfit of yours to be mucked up’.