The Collaborative International Dictionary of English v.0.48:

Truage \Tru"age\, n. [Cf. OF. truage a tax. See True.]
   1. A pledge of truth or peace made on payment of a tax.
      [Obs.] --Ld. Berners.
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   2. A tax or impost; tribute. [Obs.] --R. of Gloucester.
      [1913 Webster]