[noun] [C] - a box-shaped musical instrument, held in the hands, consisting of a folded central part with a keyboard at each end, which is played by pushing the two ends towards each otherWhen you hear accordion music in a film, you know they're trying to suggest a French atmosphere.Accordion file is US for concertina file.See at concertina.
Meaning of ACCORDION in English
Cambridge English vocab. Кембриджский английский словарь. 2012