- Also called piano accordion. a portable wind instrument having a large bellows for forcing air through small metal reeds, a keyboard for the right hand, and buttons for sounding single bass notes or chords for the left hand.
- a similar instrument having single-note buttons instead of a keyboard.
- having a fold or folds like the bellows of an accordion: accordion roof; accordion panel.
verb (used without object)
- (of a door, roof, or other covering) to open by folding back or pressing together in the manner of an accordion: The roof of the car accordions to let in sunlight and fresh air.
- to fold, crush together, or collapse in the manner of an accordion.
verb (used with object)
- to demolish by crushing together lengthwise: The impact accordioned the car beneath the truck.
- a portable box-shaped instrument of the reed organ family, consisting of metallic reeds that are made to vibrate by air from a set of bellows controlled by the player’s hands. Notes are produced by means of studlike keys
- short for piano accordion
1831, from German Akkordion, from Akkord “musical chord, concord of sounds, be in tune” (cf. Italian accordare “to attune an instrument”); ultimately from same source as English accord (v.), with suffix on analogy of clarion, etc. Invented 1829 by piano-maker Cyrill Demian (1772-1847) of Vienna.