1 definition by Lewberto
In England especially, a mag is an exceptionally short penis. The word derives from the word maggot which is the name of a wormlike insect larvae - the connection being that maggots are rather small. The word is used as an insult towards someone who is known or suspected to have a small penis. If the former is the case, then the one with the mag can duly call the insulter a pervert. Usually the accusation is false, and is believed by those who are insecure about the length of their own penis and who feel better about themselves by mocking others.
Haha look at that short kid. Because he's short he must have a mag. Let's tell him our conclusion: MAG!
by Lewberto May 26, 2009