The phrase "good deterrent" means something that keeps people from doing something bad or wrong by making them afraid of the consequences. Full definition
Because of their impressive size, they are good deterrent dogs, which makes them good guard dogs. (animalwised.com)
When Michael Howard was Employment Secretary, one of the very best deterrents for Black Economy activists - and the number is staggeringly high - was the mandatory 2 week Restart course. (conservativehome.blogs.com)
This singular microchip implanter gives the practitioner peace of mind that an implantation has been properly completed — proper implantation being the single best deterrent of microchip migration. (datamars.com)