The Collaborative International Dictionary of English v.0.48:

Prepense \Pre*pense"\, v. i.
   To deliberate beforehand. [Obs.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Prepense \Pre*pense"\, a. [See Pansy, and cf. Prepense, v.
   t.]
   Devised, contrived, or planned beforehand; preconceived;
   premeditated; aforethought; -- usually placed after the word
   it qualifies; as, malice prepense.
   [1913 Webster]

         This has not arisen from any misrepresentation or error
         prepense.                                --Southey.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Prepense \Pre*pense"\, v. t. [Pref. pre + F. penser to think.
   See Pansy.]
   To weigh or consider beforehand; to premeditate. [Obs.]
   --Spenser. Sir T. Elyot.
   [1913 Webster]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

PREPENSE. The same as aforethought. (q.v.) Vide 2 Chit. Cr. Law, *784.