Green’s Dictionary of Slang

gonnof v.

also gonif, gonnoff, gonoph, gunove
[gonnof n. (1)]

to steal, to rob, to deceive; thus gonnofing or gonophin, stealing, deception.

[UK]Dickens ‘The Detective Police’ in Reprinted Pieces (1899) 143: From the swell mob, we diverge to the kindred topics of cracksmen, fences... designing young people who go out gonophing, and other ‘schools’.
[UK]Leaves from Diary of Celebrated Burglar 93/1: There they used to talk over ‘gonnoffing,’ plan robberies, ‘fence their swag,’ leave their ‘tools,’ &c.
[UK]Sl. Dict. 184: A gun’s practice is known as gunoving.
[UK]Sporting Times 22 May 3/4: ‘Them Phillipses was always a gonophin’ lot [...] Old Abe Phillips once gave a blind man a French halfpenny an’ sneaked his dog’.
[UK]‘Morris the Mohel’ ‘Houndsditch Day by Day’ in Sporting Times 15 Feb. 2/2: Ve bowled Aaron Motzaberger out in a peautiful piece o’ gonophin the other day.
[UK]P.H. Emerson Signor Lippo 104: What’s he been up to? Gonnofing?
[Aus]Sydney Sportsman (Surry Hills, NSW) 3 Oct. 1/2: Three twopenny stamps that were on the table could not be found after Sol had left, and it’s 10 to one that he gonnoffed them.
[US]Jackson & Hellyer Vocab. Criminal Sl. 38: gonif [...] to rob.
[US]J. Ellroy ‘Hot-Prowl Rape-O’ in Destination: Morgue! (2004) 309: We gonifed a golf cart and coursed out on the course.