IPA: /ˈtiːðər/
KK: /ˈtiːðər/
A small object that babies chew on to help relieve the pain of teething.
The baby happily gnawed on the teether to soothe his sore gums.
Teether originates from the word 'teethe' (from Old English 'tithian', meaning to grow teeth). A teether is an object designed for babies to chew on as their teeth come in, helping to soothe their gums during the teething process.
Think of a baby 'growing teeth' ('teethe') and needing something to chew on — that's what a teether is for.