n. a note that alternates rapidly with another note a semitone above it
n. the articulation of a consonant (especially the consonant `r') with a rapid flutter of the tongue against the palate or uvula
v. pronounce with a trill, of the phoneme `r'
n. 颤声, 颤音, 啭鸣
vt. 用颤声说, 用颤音唱
vi. 发出颤音