The Collaborative International Dictionary of English v.0.48:

Intellection \In`tel*lec"tion\, n. [L. intellectio synecdoche:
   cf. F. intellection.]
   A mental act or process; especially:
   (a) The act of understanding; simple apprehension of ideas;
       intuition. --Bentley.
   (b) A creation of the mind itself. --Hickok.
       [1913 Webster]

WordNet (r) 3.0 (2006):

intellection
    n 1: the process of using your mind to consider something
         carefully; "thinking always made him frown"; "she paused
         for thought" [syn: thinking, thought, thought
         process, cerebration, intellection, mentation]