Definition

An endearing term for something unbearably cute, like 'munchkin' but with more syllables for extra adorableness. It's what you call small children, pets, or that one friend who's shorter than everyone else. The word itself sounds squishy and round, which perfectly matches its meaning.

Example Usage

Look at that puppy with the tiny bow tie—what an absolute umplin!

Source: Urban Dictionary (https://www.urbandictionary.com/define.php?term=umplin&defid=16022970)