Fraternize vs. Fraternise

Fraternizeverb

(intransitive) To associate with others in a brotherly or friendly manner.

Fraterniseverb

standard spelling of fraternize

Fraternizeverb

(intransitive) To associate as friends with an enemy, in violation of duty.

Fraterniseverb

be on friendly terms with someone, as if with a brother, especially with an enemy

Fraternizeverb

(intransitive) To have an intimate or sexual relationship with a forbidden member of the opposite sex; as, in some cases, football players with cheerleaders.

Fraternizeverb

To associate or hold fellowship as brothers, or as men of like occupation or character; to have brotherly feelings.

Fraternizeverb

To bring into fellowship or brotherly sympathy.

‘Correspondence for fraternizing the two nations.’;

Fraternizeverb

be on friendly terms with someone, as if with a brother, especially with an enemy

Fraternizeverb

associate or form a friendship with someone, especially when one is not supposed to

‘she ignored Elisabeth's warning glare against fraternizing with the enemy’;