nipple

/ˈnɪpəl/
noun
  1. The small, raised part in the center of a breast or udder, through which milk passes in females.
    • The doctor explained that sore nipples are common during the first weeks of breastfeeding.
    • Babies instinctively know how to latch onto the nipple to feed.
    • Mammals have nipples that provide milk to their young.
  2. A small, round, projecting part on a device, used for attaching, adjusting, or lubricating.
    • He attached the grease gun to the nipple on the tractor's axle.
    • The bicycle pump has a small nipple that fits into the valve on the tire.
    • You need to screw the hose onto the brass nipple of the faucet.
Synonyms
What does "nipple" mean? | whatsthatwordmean | whatsthatwordmean