Webster's Revised Unabridged Dictionary · 1913

Fraternize

Fraternize (? o?; 277) , intransitive verb

[Compare French fraterniser.]

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

Fraternize , transitive verb

To bring into fellowship or brotherly sympathy.
Correspondence for fraternizing the two nations. — Burke