pacifier

noun

1. a person or thing that pacifies.
2. a rubber or plastic device, often shaped into a nipple, for a baby to suck or bite on.

noun

1. a person or thing that pacifies
2. US and Canadian a baby’s dummy or teething ring

n.“one who pacifies or appeases,” 1530s, agent noun from pacify. The meaning “nipple-shaped device for babies” is first recorded 1904.