What does Yuki from the Vampire Knight often say that means "scared"?

I haven't watched the anime in a long while, but I remember when Yuki would have her flashbacks to being attacked by a vampire as a kid, she would say something along the lines of "afraid" or "scared". In Japanese I could've sworn it sounded like (ka-wai) (as in the syllable "ka" and then the letter "y"), but no translations for scared or afraid seem to be anything like that. Am I going crazy, or am I just looking for the wrong thing? It's driving me crazy, because I want to remember that word, but I can't find it. Can anyone help me?