connected with the relationship that exists between people or groups that share the same ideas or interests （指志趣相投者）兄弟般的，亲如手足的 a fraternal organization/society 兄弟会组织；共济会
connected with the relationship that exists between brothers 兄弟间的 fraternal rivalry 兄弟间的较劲
Word Originlate Middle English: from medieval Latin fraternalis, from Latin fraternus, from frater ‘brother’.