any structural anomaly of any of the small paired racemose (compound tubulo-alveolar) glands below the apex of the prostate in males, located posterolateral to the membranous portion of the urethra at the base of the penis, between the two layers of the fascia of the urogenital diaphragm, in the deep perineal pouch, and enclosed by transverse fibers of the sphincter urethrae membranaceae muscle; they secrete a clear fluid known as pre-ejaculate (Cowper's fluid), and are homologous to the greater vestibular (Bartholin's) glands in the female