The Collaborative International Dictionary of English v.0.48:

Deterrence \De*ter"rence\, n.
   That which deters; a deterrent; a hindrance. [R.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

deterrence
    n 1: a negative motivational influence [syn: disincentive,
         deterrence] [ant: incentive, inducement, motivator]
    2: a communication that makes you afraid to try something [syn:
       determent, deterrence, intimidation]
    3: the act or process of discouraging actions or preventing
       occurrences by instilling fear or doubt or anxiety