Green’s Dictionary of Slang

(Aus.) dressed up in one’s best, poss. flashy garments.

1910		Bulletin (Sydney) 3 Nov. 39/2: It’s like this: I’m goin’ to dinner at Guv’ment ’Ouse, an’ them sort o’ people thinks a lot of a bloke’s clobber, y’ know; so I’ll ’ave to go mockered up classy-like.
1915		Sun. Times (Perth) 20 June 8/8: One of the terrible punches nearly crushed the cosmetqiue on the mo. of a much mockered-up fielder.
1922		Gippsland Times (Vic.) 2 Nov. 5/2: Wiv flowers on yer braces, / Yer clever wiv yer coloured ties / [...] / Yer thinks becos yer mockered up / Yer owns th’ bloomin’ country.
1937–84		Partridge DSUE.
1943		Baker Popular Dict. Aus. Sl. (2nd edn).
1957		D. Niland Call Me When the Cross Turns Over (1958) 174: Don’t think of the Apostles as silvertails, all mokkered up in the best, and a cheque-book for every pocket.
1977		D. Stuart Drought Foal 180: Or an Admiral, any of them coves, all mockered up, real bloody desert lairs?
1988		McGill Dict. of Kiwi Sl. 73/1: mockered up dressed up, specifically from 1935 woman’s dress.
2002		Joyzine ‘Strine Decoded’ 🌐 all laired/mockered up – dressed in one’s best clothes.
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].