1. Turn away from by persuasion
   "Negative campaigning will only deter people";
   - dissuade
    
2. Try to prevent; show opposition to
   "We should deter this practice among our youth";
   - discourage

Derived forms: deters, deterring, deterred

Type of: advise, counsel, disapprove, rede [archaic], reject

Antonym: persuade

Encyclopedia: Deter