Also ganev, gonif, goniff,
Yiddish: גאַנעוו
Ganef is the form popularized in Mad Magazine.
Thief, from ganvenen, to steal.
Dem Ganefs Yiches (The Thief's Lineage) is a popular Klezmer song.
Dayn mutter ganvet fisch im markt.
Your mother steals fish in
the market.