Wordnet 3.0
ADJECTIVE (2)
1. 
 depriving of confidence or hope or enthusiasm and hence often deterring action; 
- Example: "where never is heard a discouraging word"2. 
 expressing disapproval; 
The Collaborative International Dictionary of English v.0.48:
Discourage \Dis*cour"age\ (?; 48), v. t. [imp. & p. p.
   Discouraged; p. pr. & vb. n. Discouraging.] [Pref. dis- +
   courage: cf. OF. descoragier, F. d['e]courager: pref. des-
   (L. dis-) + corage, F. courage. See Courage.]
   1. To extinguish the courage of; to dishearten; to depress
      the spirits of; to deprive of confidence; to deject; --
      the opposite of encourage; as, he was discouraged in his
      undertaking; he need not be discouraged from a like
      attempt.
      [1913 Webster]
            Fathers, provoke not your children to anger, lest
            they be discouraged.                  --Col. iii.
                                                  21.
      [1913 Webster]
   2. To dishearten one with respect to; to discountenance; to
      seek to check by disfavoring; to deter one from; as, they
      discouraged his efforts.
   Syn: To dishearten; dispirit; depress; deject; dissuade;
        disfavor.
        [1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Discouraging \Dis*cour"a*ging\, a.
   Causing or indicating discouragement. --
   Dis*cour"a*ging*ly, adv.
   [1913 Webster]
WordNet (r) 3.0 (2006):
discouraging
    adj 1: depriving of confidence or hope or enthusiasm and hence
           often deterring action; "where never is heard a
           discouraging word" [ant: encouraging]
    2: expressing disapproval
Moby Thesaurus II by Grady Ward, 1.0:
45 Moby Thesaurus words for "discouraging":
   admonitory, alarming, awing, black, bleak, cautionary, chilling,
   daunting, depressant, depressing, depressive, deterrent, deterring,
   disconcerting, disheartening, disinclining, dismal, dismaying,
   dispiriting, disquieting, dissuading, dissuasive, down, dreary,
   expostulatory, fear-inspiring, fearful, fearsome, forbidding,
   forestalling, frightening, frightful, hindering, intimidating,
   monitory, oppressive, overawing, preclusive, preventative,
   preventive, prohibitive, prophylactic, scaring, scary, startling