deterrent-n; 2 Senses

Sense Number 1: a context or situation that hinders or impedes

Commentary: DETERRENT[+state][+condition][+pejorative][+obstruction] [+relation][+role][-beneficial]
NOTE: has a pejorative connotation

Don't let his cynical remarks be a deterrent to your enjoyment of the play.
The mud proved to be a major deterrent to getting medical aid quickly to the victims.
Her micromanagement of that department has been a major deterrent to creativity and innovation.

WordNet 3.0 Sense Numbers: 1

Sense Number 2: something which prevents a bad situation, or protects one

Commentary: DETERRENT[+state][+condition][-pejorative][+protection] [+relation][+role][+beneficial]
NOTE: does not have a pejorative connotation (see Sense 1)
NOTE: can be beneficial, e.g., occurs in phrases 'a good deterrent'

A watch dog is a good deterrent for would-be burglars.
How long nuclear weapons will remain a deterrent to a world war is anyone's guess.
It was argued that a pre-emptive strike would be a deterrent to further acts of terrorism.

WordNet 0.0 Sense Numbers: 2