||Ap`o*neu*ro"sis (&?;), n.; pl. Aponeuroses (&?;). [Gr. &?;, fr. &?; to pass into a tendon; &?; from + &?; to strain the sinews, &?; sinew, tendon, nerve.] (Anat.) Any one of the thicker and denser of the deep fasciæ which cover, invest, and the terminations and attachments of, many muscles. They often differ from tendons only in being flat and thin. See Fascia.