The Collaborative International Dictionary of English v.0.48:

Feu \Feu\ (f[=u]), n. [See 2d Feud, and Fee.] (Scots Law)
   A free and gratuitous right to lands made to one for service
   to be performed by him; a tenure where the vassal, in place
   of military services, makes a return in grain or in money.
   --Burrill.
   [1913 Webster]