Monochord

n. [ L. monochordon, Gr. &unr_;, fr. &unr_; with but one string; &unr_; only, single + &unr_; 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. [ 1913 Webster ]

n. [ Gr. nw^ton the back + E. chord. ] (Anat.) An elastic cartilagelike rod which is developed beneath the medullary groove in the vertebrate embryo, and constitutes the primitive axial skeleton around which the centra of the vertebrae and the posterior part of the base of the skull are developed; the chorda dorsalis. See Illust. of Ectoderm. [ 1913 Webster ]