Anat. [L. complexus, pa. pple. of complecti (with musculus understood; cf. biceps, etc.); so called from its manifold subdivisions and points of attachment.] A large muscle attached to the vertebræ of the neck and upper part of the back, which serves to bend the head back.
1831. R. Knox, Cloquet’s Anat., 253. The Complexus is a pretty thick elongated muscle … situated under the splenius.
