prostate gland

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A gland in male mammals surrounding the urethra at the base of the bladder that controls release of urine from the bladder and secretes a fluid which is a major constituent of semen.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun anatomy A gland in male mammals surrounding the urethra just below the urinary bladder that controls the release of urine from the bladder and produces a secretion that is the fluid part of semen.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a firm partly muscular chestnut sized gland in males at the neck of the urethra; produces a viscid secretion that is the fluid part of semen