deterrent

adjective

1. serving or tending to deter.

noun

2. something that deters: a deterrent to crime.
3. military strength or an ability to defend a country or retaliate strongly enough to deter an enemy from attacking.

noun

1. something that deters
2. a weapon or combination of weapons, esp nuclear, held by one state, etc, to deter attack by another

adjective

3. tending or used to deter; restraining

1829, noun and adjective, in Bentham, from Latin deterrentem, present participle of deterrere (see deter). In reference to nuclear weapons, from 1954.