The Collaborative International Dictionary of English v.0.48:

Premeditate \Pre*med"i*tate\, v. t. [imp. & p. p. Premeditated
   (-t[=a]`t?d); p. pr. & vb. n. Premeditating.] [L.
   praemeditatus, p. p. of praemeditari; prae before + meditari
   to meditate. See Meditate.]
   To think on, and revolve in the mind, beforehand; to contrive
   and design previously; as, to premeditate robbery.
   [1913 Webster]

         With words premeditated thus he said.    --Dryden.
   [1913 Webster]

WordNet (r) 3.0 (2006):

premeditated
    adj 1: characterized by deliberate purpose and some degree of
           planning; "a premeditated crime" [ant: unpremeditated]