The Collaborative International Dictionary of English v.0.48:

Imprest \Im*prest"\ ([i^]m*pr[e^]st"), v. t. [ imp. & p. p.
   Imprested; p. pr. & vb. n. Impresting.] [Pref. im- +
   prest: cf. It. imprestare. See Prest, n.]
   To advance on loan. --Burke.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Imprest \Im"prest\ ([i^]m"pr[e^]st), n. [Cf. It. impresto,
   imprestito, LL. impraestitum. See Imprest, v. t., and
   Impress compulsion to serve.]
   A kind of earnest money; loan; -- specifically, money
   advanced for some public service, as in enlistment. --Burke.
   [1913 Webster]

         The clearing of their imprests for what little of their
         debts they have received.                --Pepys.