fraternize vs fraternise

fraternize and fraternise both are verbs.

Word	Noun	Adjective	Verb	Adverb
fraternize	No	No	Yes	No
fraternise	No	No	Yes	No

As verbs, fraternize and fraternise are synonyms defined as:

fraternize and fraternise: be on friendly terms with someone, as if with a brother, especially with an enemy

fraternize (verb)	fraternise (verb)
be on friendly terms with someone, as if with a brother, especially with an enemy	be on friendly terms with someone, as if with a brother, especially with an enemy