Definition of Nipple

Nipple: The pigmented projection on the surface of the chest in the male and the breast in the female. In the mature female, ducts that conduct milk from the mammary glands to the surface of the breast exit through the nipple. The surrounding flat area of pigmentation is the areola.

Source: MedTerms™ Medical Dictionary
http://www.medterms.com/script/main/art.asp?articlekey=4566
Last Editorial Review: 3/19/2012