Green’s Dictionary of Slang

mucked (out) adj.

penniless.

1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1835		G. Kent Modern Flash Dict.
1848		Flash Dict. in Sinks of London Laid Open.
1859		Hotten Dict. of Modern Sl. etc. 64: MUCKED OUT, lost everything, — generally used in gambling.
1860		Hotten Dict. of Modern Sl. etc. [as cit. 1859].
1873		Graphic (London) 9 Aug. 9/1: Doubtless backers of favourites, with their pockets full of money on Tuesday evening [...] were neatly, if not quite ‘mucked out’ by the next.
1913		H. Lawson ‘Benno and his Old ’Uns’ in Roderick (1972) 805: Her Old ’Un ‘shickered’ till he got ‘mucked’ every pay day.