The Collaborative International Dictionary of English v.0.48:

Stackage \Stack"age\ (st[a^]k"[asl]j), n.
   1. Hay, grain, or the like, in stacks; things stacked. [R.]
      [1913 Webster]

   2. A tax on things stacked. [R.] --Holinshed.
      [1913 Webster]