/trɪl; trɪl/
n
1 vibrating sound made by the voice or in bird song （人或鸟发出的）颤动声.
2 (music 音) (sound of) two notes a tone or a semitone apart being played or sung several times one after the other （音的）颤动; 颤音.
3 speech sound made by pronouncing `r' while vibrating the tongue （舌的）颤音, 颤动辅音.

v [I, Ip, Tn]
1 sound or sing (a musical note) with a trill 用颤音发声; 用颤音唱（某乐音）
*The canary was trilling away in its cage. 那只金丝雀在笼中鸣啭.
2 pronounce (a letter) with a trill 用颤音发（某字母）的音; 发某字母的颤音.