Green’s Dictionary of Slang

to dress up.

1879		‘Autobiog. of a Thief’ in Macmillan’s Mag. (London) XL 501: I used to clobber myself up and go to the concert-rooms.
1887		W.E. Henley ‘Villon’s Good-Night’ in Farmer Musa Pedestris (1896) 174: You judes that clobber for the stramm, / You ponces good at talking tall.
1893		P.H. Emerson Signor Lippo 55: One day he walked straight into this kitchen clobbered in a pair of rounds, tight to his legs, [...] and a long sleeve cadi on his napper.
1901		Sydney Sportsman (Surry Hills, NSW) 1 May 1/6: Clobbered up in style and fashion / Loud as any German band.
1901		W.S. Walker In the Blood 47: I ain’t allays too well clobbered. This is my Sunday-go-to-meetin’s I’ve got on.
1906		E. Pugh Spoilers 4: Bin ’angin’ about the Scrubbs an’ then ’ere for nigh on three weeks, I ’ave, clobbered up like this.
1909		J. Ware Passing Eng. of the Victorian Era 94/1: ‘Thank God,’ she observed, ‘I’ve got a costume play at last. I shall klobber in Crimson and gold for the first act, blue and amber for the second, and pure white and silver for my death in the third. I shall make a great success.’ [Ibid.] 163/2: So I klobbered myself up as well as circs would permit.