Swollen erectiveness of the nipple (or nipples) due to physical (or in some cases, mental) stimulation such as; licking, flicking, biting, sucking, freezing, burning (
candle wax), piercing, applying anything
mentholated, slamming in a door, stretching because you used them to hang heavy objects from, etc. Shredding of one's upper garments, damage to glass and
accidental injury to others are common due to the knifelike nature of the affected nipple.