chord1

Origin:

Middle English cord, from accord. The spelling change in the 18th century was due to confusion with chord². The original sense was 'agreement, reconciliation', later 'a musical concord or harmonious sound'; the current sense dates from the mid 18th century

See chord² (usage)

Do not confuse chord with cord. Chord means 'a group of musical notes' (a G major chord), whereas cord means 'thin string or rope' or 'a part of the body like a string or rope' (the spinal cord).