warble
1. war.ble \'wo.r-b*l\ n [ME werble tune, fr. ONF, of Gmc origin; akin to MHG wirbel whirl,]tuning peg, OHG wirbil whirlwind - more at WHIRL 1: a melodious succession of low pleasing sounds 2: a musical trill 3: the action of warbling 2. warble \-b(*-)lin\ vb or war.bling 1: to sing in a trilling manner or with many turns and variations 2: to become sounded with trills, quavers, and rapid modulations in pitch 3: SING : to render with turns, runs, or rapid modulations : TRILL 3. warble \-b*ld\ n [perh. of Scand origin; akin to obs. Sw varbulde boil, fr. var pus]+ bulde swelling 1: a swelling under the hide esp. of the back of cattle, horses, and some o ther mammals caused by the maggot of a botfly or warble fly 2: the maggot of a warble fly - war.bled aj
 Webster's English Dictionary
 Webster's English Dictionary