The Collaborative International Dictionary of English v.0.48:

Causation \Cau*sa"tion\, n.
   The act of causing; also the act or agency by which an effect
   is produced.
   [1913 Webster]

         The kind of causation by which vision is produced.
                                                  --Whewell.
   [1913 Webster]

   Law of universal causation, the theoretical or asserted law
      that every event or phenomenon results from, or is the
      sequel of, some previous event or phenomenon, which being
      present, the other is certain to take place.
      [1913 Webster]

WordNet (r) 3.0 (2006):

causation
    n 1: the act of causing something to happen [syn: causing,
         causation]