Green’s Dictionary of Slang

zob n.

[note Jan Ivarsson on American Dialect Society-List 23/3/03: ‘“Zob” with the variants “zobi”, “zeb” or “zébi” is well established in French slang since at least 1870 [...] It comes from maghrebin Arabic “zebbi” or classical Arabic “zubb”. The sense of the word is “penis”, and it is very often used pejoratively about a person.’]

(US) a good-for-nothing, a weak person.

[US]B. Fisher A. Mutt in Blackbeard Compilation (1977) 113: Strike? You big zob, I got a mind to crush you on the knob.
Lincoln (NE) Eve. News 1 July B-7: Every time we look at those sad married men – having their money saved for them every week instead of spending it freely pay night and going around for a touch the next day – poor zobs. They even seem to like it.
Bulletin (San Francisco) 17 Sept. 12/3: When Chicago secured Leach from Pittsburg on a deal the wise zobs chirped: ‘What’s Murphy want of that old fossil?’ It did look like vintage, but nevertheless, and a couple notwithstandings, Leach pulled himself together and has, and is, playing a sensational out field for the Cubs.
[US]S. Lewis Main Street (1921) 416: Next time you hear some zob from Yahooville-on-the-Hudson chewing the rag and bulling and trying to get your goat tell him that no two-fisted enterprising Westerner would have New York for a gift!
[US]S. Lewis Babbitt (1974) 115: The poor zob that hasn’t got any will-power.
[US]Berrey & Van den Bark Amer. Thes. Sl.