fraternize

动词 fraternize:

1. be on friendly terms with someone, as if with a brother, especially with an enemy
   同义词：fraternise

1. Army personnel are often forbidden to fraternize with the civilian population.
   军职人员常被禁止与平民百姓友好往来。
2. Soldiers who fraternize with the enemy will be punished.
   亲敌的士兵将受到惩罚。

frat.er.nize

v.intr.（不及物动词）
frat.er.nized,frat.er.niz.ing,frat.er.niz.es
To associate with others in a brotherly or congenial way.
亲如兄弟：以兄弟般的或友善的方式与他人交往
To associate on friendly terms with an enemy or opposing group, often in violation of discipline or orders.
亲敌：同敌人或敌对的团体友好地（常违反原则或命令地）交往

来源：
French fraterniser
法语 fraterniser
from Medieval Latin fr3terniz3re
源自 中世纪拉丁语 fr3terniz3re
from Latin fr3ternus [fraternal] * see fraternal
源自 拉丁语 fr3ternus [兄弟般的] *参见 fraternal

【引伸】
frat.erniza.tion
frat.erniz.er
n.（名词）