An acronym for "All Age Club Master." All age club events occur when a separate venue rents out a night club, and allows any age person to enter, often causing the crowd to be young and immature. An AACM is a person, usually a male, who is an expert at exploiting these all age events for all they are worth. They are masters of grinding, a special type of dancing in which a female rubs her behind on a males genital region. AACM's will target all females, as their goal is to dance with as many females as possible. AACM's take pride in their attire - the typical AACM outfit consists of of a button-down shirt with many of the buttons not actually being buttoned, and stylish jeans that are often adorned with studs, chains, or deep, philosophical quotes on the behind. AACM's utilize Facebook to find all age events, and always click "attend" to show just how much of a true AACM they are.
My friend danced with 20 girls last night at the all age event at the hookah bar. He's an AACM!!!