n.
Function: noun
Etymology: Italian trillo probably of imitative origin
Date: 1649
1 a : the alternation of two musical tones a diatonic second apart ― called also shake b : VIBRATO c : a rapid reiteration of the same tone especially on a percussion instrument
2 : a sound resembling a musical trill : WARBLE
3 a : the rapid vibration of one speech organ against another (as of the tip of the tongue against the teethridge) b : a speech sound made by a trill