The spiv reached his apotheosis during World War II and the succeeding years, when the disrupted economic conditions allowed ample scope for unofficial trading (a pair of nylons here, a few packets of cigarettes there) and other petty crime. He became a stock figure in the English social comedy, represented on screen by such stereotypes as 'Flash Harry' (played by George Cole) in the St. Trinian's films and Pte. Walker in Dad's Army. [Ayto, "20th Century Words"]
[spiv etymology, spiv origin, 英语词源]