WordWeb Online

1. Depriving of confidence or hope or enthusiasm and hence often deterring action
   "where never is heard a discouraging word"
    
2. Expressing disapproval

1. Try to prevent; show opposition to
   "We should discourage this practice among our youth"
   - deter
    
2. Deprive of courage or hope; take away hope from; cause to feel discouraged
    
3. Admonish or counsel in terms of someone's behaviour
   "I discouraged him not to go too far"
   - warn, admonish, monish
    
4. Try to persuade somebody not to do something

See also: daunting, demoralising [Brit], demoralizing, discouragement, discouragingly, disheartening, dispiriting, dissuasive, frustrating, hopeless, intimidating, unencouraging, unhelpful

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

Antonym: encourage, encouraging