ceriti

1. colloq. (ceriti se) to grin
   Što se tako ceriš? — What are you grinning like that for?
   Ceri se od uha do uha. — He's grinning from ear to ear.
2. colloq. derog. (ceriti se + dat.) to sneer; to grin mockingly
   Cerio mi se u lice dok sam pričao. — He was sneering in my face while I was talking.

Used almost always with "se".