The Collaborative International Dictionary of English v.0.48:

Arrentation \Ar`ren*ta"tion\ [Cf. F. arrenter to give or take as
   rent. See Arendator.] (O. Eng. Law)
   A letting or renting, esp. a license to inclose land in a
   forest with a low hedge and a ditch, under a yearly rent.
   [1913 Webster]