(ethnic slur) Alternative letter-case form of Jerry (“a German”).
noun
(UK, thieves' cant, obsolete) A watch (timepiece).
R. Austin Freeman, A Savant's Vendetta
'Do you know a jerry when you sees one — a red 'un, mind you?' […] The fellow looked furtively at the door and then, diving into an inner pocket, pulled out a handsome gold watch with a massive chain attached, exhibited it for a moment and then dropped it back.