Green’s Dictionary of Slang

to invigorate, to cheer up, to improve morale.

1819		‘One of the Fancy’ Tom Crib’s Memorial to Congress 24: In vain did they try to fig up the old lad, / ’Twas like using persuaders upon a dead prad.
1865		R.S. Surtees Facey Romford’s Hounds 87: You know what I want, and must fig your fellows up to giving it.