nipple
Pronunciation: /ˈnɪp(ə)l/
noun
- 1the small projection in which the mammary ducts of female mammals terminate and from which milk can be secreted.
- the vestigial structure in a male that corresponds to the nipple of a female mammal.
- North American the teat of a feeding bottle: it is crucial to remove the cap or nipple of the baby’s bottle before heating
- 2a small projection on a device, especially one from which oil or other fluid is dispensed: the centralized greasing point comprises a bank of seven nipples
- a short section of pipe with a screw thread at each end for coupling: install a threaded nipple between the valve outlet and the shut-off inlet

Origin:
mid 16th century (also as neble, nible): perhaps a diminutive of neb