Cera. Perchè non usi un dizionario online? :-) http://www.wordreference.com/

Idioma italiano: --- che brutta cera che hai! Che ti succede ? meaning: you look either angry, sad, with some bad mood, or just without a good sleep during the night; /cera/ here means how in this moment your face looks like; Even beautiful women or handsome men could have a /brutta cera/, depending on their momentary situation.