The Collaborative International Dictionary of English v.0.48:
Pannage \Pan"nage\, n. [OF. pasnage, LL. pasnadium, pastinaticum, fr. pastionare to feed on mast, as swine, fr. L. pastio a pasturing, grazing. See Pastor.] (O. Eng. Law) (a) The food of swine in the woods, as beechnuts, acorns, etc.; -- called also pawns. (b) A tax paid for the privilege of feeding swine in the woods. [1913 Webster]