The Collaborative International Dictionary of English v.0.48:

Impresa \Im*pre"sa\ ([-e]m*pr[=a]"s[.a]), n. [It. See Emprise,
   and cf. Impress, n., 4.] (Her.)
   A device on a shield or seal, or used as a bookplate or the
   like. [Written also imprese and impress.]
   [1913 Webster]

         My impresa to your lordship; a swain
         Flying to a laurel for shelter.          --J. Webster.
   [1913 Webster]