An Adult Baby is a grown up male or female who enjoys spending time mentally regressing to a younger baby or child-like state, they prefer the freedom of resposibilities that this time offers them, it is a form of escapism and relief.  They like to express their emotions in play and forget about grown up issues.

This is often characterised by, but not exclusively, props to help them achieve that mental state, usually the wearing of babyish attire, predominantly a nappy or diaper (either cloth or disposible ) and sometime suckling on a dummy, drinking from a bottle and playing with toys of a particular era that means something to them etc. They like giving over responsibility to either a dominant of the opposite sex who takes a paternal or maternal role as the care giver.