A term of endearment and adoration for a cute, baby-like loved one with supple, round cheeks. The use of the term is often accompanied by a game of exchanging noisy kisses or utterances of frustration regarding how the other person doesn't love them anymore in a baby-like, ungrammatical manner.
Poochki Paachki, You're soooo cuuuute!! <while planting noisy kisses on the other's cheeks.> How come you don't love me no more?!