sphincter urethrae

noun

sphincter ure·​thrae -yu̇-ˈrē-thrē 

: a muscle composed of fibers that arise from the inferior ramus of the ischium and that interdigitate with those from the opposite side of the body to form in the male a narrow ring of muscle around the urethra just distal to the apex of the prostate gland and in the female a ring of muscle more generally distributed around the urethra

called also urethral sphincter