frighten, frightens, frightening, frightened, to scare, scare
Mnemonic
[xi-] Xena is in the [4] bathroom of the [-a] auditorium where it is eerily empty and dark. Even the bathroom attendants are missing. She hears a 吓 frightening sound from 下 below the bathroom tile, so uses her sword to pry it open. Right there, 下 below her, is a talking 口 mouth that recites 吓 frightening Shakespeare lines to her. She is so 吓 frightened that she runs away and into one of the bathroom stalls.