An 18-20 year old human.
Mom: "Happy Birthday, son! You're 18 years old today, wow!"
Son: "Thanks, Mom. Yup, I'm an ADULT now! Legally I can do whatever I want and you can't ground me."
Mom: laughs "Adult? You're a BABY adult."
by Princess Butterfly June 26, 2017
Get a baby adult mug for your dog José.
When one dresses and acts like a baby, Having to be cared for in every way by a mommy, daddy, or both.
Adult Baby Joe has a mommy that feeds him and changes his soiled nappies
by Leshrec November 01, 2006
Get a Adult Baby mug for your boyfriend Georges.
Noun
Also referred to as AB
A person who acts like an infant or baby. Normally dresses up in a variety of baby like clothing like diapers, onesies, bibs, sleepers, and kid like shirts. Some adult babies find comfort and security in diapers and being cared by a mother or father. The age range for adult babies can vary from newborns to toddlers. Adult babies do not find sexual arousal out of diapers unlike diaper lovers (DL)
That Adult Baby isn't exactly the most normal. All he does is sit their like a read baby and have his mothers change him.
by Broken-Steel-Rocks June 29, 2009
Get a Adult Baby mug for your girlfriend Rihanna.
An Adult that acts like a baby e.g getting their nappy changed by someone else.
"Have you seen that adult baby next door? He's so weird!"
by Fernus123 August 31, 2015
Get a Adult baby mug for your cousin Manley.