trill\ntril/Submit\nnoun\n1.\na quavering or vibratory sound, especially a rapid alternation of sung or played notes.\nthey heard the muffled trill of the telephone\nverb\n1.\nproduce a quavering or warbling sound.\na skylark was trilling overhead\nsynonyms: warble, sing, chirp, chirrup, tweet, twitter, cheep, peep\nsongbirds trill their sweet music