Source : Webster's Revised Unabridged Dictionary (1913)

Urethra \U*re"thra\, n. [L., fr. Gr. ?. See {Urine}.] (Anat.)
   The canal by which the urine is conducted from the bladder
   and discharged.

Source : WordNet®

urethra
     n : duct through which urine is discharged in most mammals and
         which serves as the male genital duct
     [also: {urethrae} (pl)]