资料来源 : pyDict

结拜兄弟;刎颈之交,莫逆之交

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Sworn \Sworn\,
   p. p. of {Swear}.

   {Sworn brothers}, originally, companions in arms who took an
      oath to share together good and bad fortune; hence,
      faithful friends.

   {Sworn enemies}, determined or irreconcilable enemies.

   {Sworn friends}, close friends.