chord [ME] The sense of a group of musical notes was originally spelt cord and was a shortening of accord [ME] in the sense ‘bring into harmony’, which came from Latin accordere literally ‘to bring to heart’. The accordion [M19th] ultimately gets its name from the same source. The sort of chord found in mathematics is also a respelling of cord, but this time in the sense ‘rope’. This was a Middle English word from Latin chorda, which came in turn from Greek khorde ‘gut, string of a musical instrument’. The spellings of both chords was changed to be more like their classical sources.