myotome

n. [ See Myotomy. ] (Anat.) (a) A muscular segment; one of the zones into which the muscles of the trunk, especially in fishes, are divided; a myocomma. (b) One of the embryonic muscular segments arising from the protovertebrae; also, one of the protovertebrae themselves. (c) The muscular system of one metamere of an articulate. [ 1913 Webster ]