nipple

The story

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" .

First known use, by meaning

• from 16th c. The projection of a mammary gland from which, on female therian mammals, milk is secreted.
• from 16th c. A mechanical device through which liquids or gases can be passed in a regulated manner.
• from 17th c. An artificial nipple (noun sense 1) used for bottle-feeding infants.
• from 19th c. A perforated segment that fits into part of the breech of a muzzle-loading gun, on which the percussion cap is fixed.
• from 19th c. A short tube threaded at both ends, used as a connector.
• from 20th c. An internally threaded piece which holds a bicycle spoke in place on the rim.