A moistie is a rediculously HOT young girl (preferably between the ages of 16 and 16 and 1/2) who, while illegal to sleep with, can clean your house, water your lawn, make you dinner, etc. Moisties like to be around males 3-5 years older than they are, and often get 'played'. Every hot girl was once a moistie (See Moistie Alumni
) or will be a moistie (See Moistie Cadet
Hailing from a cool way of saying "wet behind the ears", some say the origin of 'moistie' traces back to 2000 in Los Alamos, NM.