teether or soother is used for babies who are teething. meaning, their teeth are coming out and their gums feels itchy,so mothers gave teether to let them chew on it. pacifier or dummy is different , it's like a nipple for bottle feed babies, but without the bottle itself. it's for babies to suck not chew. see the difference? :)

British English: dummy American English: pacifier

I call it a "pacifier". But yes, it's also known as a "soother" or "dummy".

I use "a pacifier" (read that as you will). Or alternately, "a dummy" (again, read that as you will).

We call it,, "pacifier ' :-)