You searched for: “pacifier
pacifier (s) (noun), pacifiers (pl)
1. A device used for an infant to suck or to bite on.
2. A rubber or plastic nipple or teething ring for a baby to suck or to chew on.
3. Someone who tries to bring peace.

This artificial nipple, usually made of plastic, is used so an infant can gain some solace and quiet down. A pacifier is called by other names in other countries including a "dummy" in the U.K.