nipple

The projection of a mammary gland from which, on female therian mammals, milk is secreted.

Mary felt annoyed at the girl; just because bras had become passé, did a girl with so pronounced a bosom have to cater to fashion? In this case practicality dictated a bra, and Mary stood at the desk feeling herself flushing with disapproval. And artificial nipple-dilation; it was just too much.

The nipple (definition 1) and the areola together.

Joan Trieste wore skin-tight dark pants and slippers and a cotton man’s-style shirt; as far as he could tell, she had on no bra, as fashion dictated, but her nipples were merely flat dark circles beneath the white cotton fabric of her shirt: she could not afford or did not care to have the currently-popular dilation operation.

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.

To fit (a baby's bottle, etc.) with a nipple.

To give one's nipple to (a baby) to allow breastfeeding.