The story
From adult + baby. Popularized 1980s, largely replacing infantilist outside psychology.
Etymology from Wiktionary, CC BY-SA 4.0.
adult baby
a·dult ba·byToday it means: An adult person who enjoys role-playing a regression to an infant-like state and acting like a baby or toddler, as through wearing diapers, engaging in babylike activities, babbling, etc., generally for sexual gratification. Full definition →