Nipple
mid 16th century (also as neble, nible ): perhaps a diminutive of neb.
wiktionary
From earlier neple, nypil, neble, believed to be a diminutive of nib, neb(“tip, point”), equivalent to nib + -le. Compare Old English nypel(“elephant trunk”), formed analogously as "a protuberance from one's neb" .
etymonline
nipple (n.)
1530s, nyppell, "protuberance of a mammalian breast," in a female the extremity where the milk-ducts discharge, alteration of neble (1520s), probably diminutive of neb "bill, beak, snout" (see neb), hence, literally "a small projection." Used from 1713 of any thing or mechanical part that projects like a nipple. From 1875 in reference to the mouthpiece of an infant's nursing-bottle. Earlier words were pap (n.2), teat. A 16c.-17c. slang term for a woman's nipples was cherrilets.
