\Mon"o*chord\, n. [L. monochordon, Gr. ?, fr. ? with
but one string; ? only, single + ? string: cf. F. monocorde.
See {Chord}, and cf. {Mainchord}.] (Mus.)
An instrument for experimenting upon the mathematical
relations of musical sounds. It consists of a single string
stretched between two bridges, one or both of which are
movable, and which stand upon a graduated rule for the
purpose of readily changing and measuring the length of the
part of the string between them.