Green’s Dictionary of Slang

cabbage n.1

[? corruption of 17C SE garbage/carbage, shreds and patches used as padding; predated by hell or eye: ‘From the first, when taxed with their knavery, they equivocally swear, that if they have taken any they wish they may find it in hell! or, alluding to the second protest, that what they have over and above is not more than they could put in their eye. Now generally termed cabbage’ (Hindley, The Old Book Collector’s Miscellany, 1871–3)]

1. [mid-17C–19C] (also cabbage leaf) small off-cuts of material, taken from the job in hand and sold off as perks by tailors.

2. [late 17C–19C; 1930s] a tailor.

In compounds

cabbage monger (n.) (also cabbage contractor, ...eater)

[18C–19C] a tailor.