A person (more likely male) who has a more tan right arm than left. This is a sign that the person is often the passenger in a car. May well indicate a have lack of independence and a bummer of freeloader rides. Example: Girl 1: I think Alec is kind of cute... Girl 2: Oh, no way! He's got passenger's arm!
PASSENGER'S ARM
Meaning of PASSENGER'S ARM in English
Slang English vocab. Английский сленговый словарь. 2012