heinie
n.— Note: Perhaps a play off of “Heinie,” now outdated slang for a German. «The evening crowd at Kirmser’s dressed like everyone else, the men with our hair clipped short, sometimes in a military-cut heinie.» —by Ricardo J. Brown, William Reichard The Evening Crowd at Kirmser’s , 2001. (source: Double-Tongued Dictionary)
“Heinie” is an old slang word for “buttocks”. I heard it amongst my Polish-German Wisconsin relatives during the 1950s.