Kinktionary
More like guidelines and a lot less like definitions.
babygirl
A person who seeks a parental and/or nurturing figure in a relationship, with some identifying as or role-playing as a young girl.
It is also used as a term of endearment for a female-identified submissive or bottom.
For the left-of-slash counterpart to this role, consider Caregiver, Mommy, and Daddy. For non-feminine alternatives, consider babyboy or little.