Someone who gets high off of water. Mainly by shooting up on distilled water but in rare instances water can be takin faster by means of the anus although this not for the amature because in most instances the aquaddict will appear to have shit their pants.
Katie skipped class so she could inject herself with water she is a serious aquaddict.
Curious Person: "Is it just me or did Katie shit herself?"
Me: "No I just saw her sitting on a water fountain shootin up on h20 she is an aquaddict....wait no she smells, she deffinately shit herself."