pasteurizer vs pasteuriser

pasteurizer and pasteuriser both are nouns.

Word	Noun	Adjective	Verb	Adverb
pasteurizer	Yes	No	No	No
pasteuriser	Yes	No	No	No

As nouns, pasteurizer and pasteuriser are synonyms defined as:

pasteurizer and pasteuriser: an apparatus for pasteurizing substances (especially milk).

pasteurizer (noun)	pasteuriser (noun)
an apparatus for pasteurizing substances (especially milk).	an apparatus for pasteurizing substances (especially milk).