appetizer vs appetiser

appetizer and appetiser both are nouns.

Word	Noun	Adjective	Verb	Adverb
appetizer	Yes	No	No	No
appetiser	Yes	No	No	No

As nouns, appetizer and appetiser are synonyms defined as:

appetizer and appetiser: food or drink to stimulate the appetite (usually served before a meal or as the first course)

Other synonyms of appetizer include starter.

appetizer (noun)	appetiser (noun)
food or drink to stimulate the appetite (usually served before a meal or as the first course)	food or drink to stimulate the appetite (usually served before a meal or as the first course)