colloquial A musical instrument consisting of two hard ends connected by a bellows that one alternates between pulling and squeezing the so that the bellows draws in and then expels air, which passes over a vibrating to create the desired sound. Usually refers specifically to an accordion or concertina. Most kids his age want to play the drums or electric guitar, but he has always had a fascination with the squeezebox, of all things. My granddad could liven up any room just by picking up his squeezebox and playing some jaunty tune.