The Collaborative International Dictionary of English v.0.48:

Prest \Prest\, a. [OF. prest, F. pr[^e]t, fr. L. praestus ready.
   Cf. Presto.]
   1. Ready; prompt; prepared. [Obs.]
      [1913 Webster]

            All prest to such battle he was.      --R. of
                                                  Gloucester.
      [1913 Webster]

   2. Neat; tidy; proper. [Obs.] --Tusser.
      [1913 Webster]

   Prest money, money formerly paid to men when they enlisted
      into the British service; -- so called because it bound
      those that received it to be ready for service when called
      upon.
      [1913 Webster]