nipple

Definitions

• (anatomy) The projection of a mammary gland from which, on female mammals, milk is secreted.
• A mechanical device through which liquids or gases can be passed in a regulated manner.
• An artificial nipple (definition 1) used for bottle-feeding infants.
• Any small physical protrusion, such as the lumps on the F and J keys on computer keyboards.
• Any small physical protrusion on an automotive, a machine part or any other part that fits into a groove on another part.
• (now) A perforated segment that fits into part of the breech of a muzzle-loading gun, on which the percussion cap is fixed.
• (chiefly) A short tube threaded at both ends, used as a connector.
• An internally threaded piece which holds a bicycle spoke in place on the rim.