One of those bullshit rhymes you said back in elementary school when some cock-juggling thundercunt decided to cut in line at the drinking fountain, lunch, etc.
this word is used to describe a person or thing that is characterized by the quality of cuteness; it may also be used as a noun much like the word fatso.
1) Geez, Lucy, what a cuteso (adj.) scarf you're wearing today!
2) Aw, he is such a cuteso (n.)!