Source : Webster's Revised Unabridged Dictionary (1913)

League \League\, v. i. [imp. & p. p. {Leagued}; p. pr. & vb. n.
   {Leaguing}.] [Cf. F. se liguer. See 2d {League}.]
   To unite in a league or confederacy; to combine for mutual
   support; to confederate. --South.