dissuasive

from WordNet (r) 3.0 (2006)

dissuasive
    adj 1: deterring from action; "dissuasive advice"; "made a
           slight dissuasive gesture with her hand" [ant:
           {persuasive}]

from The Collaborative International Dictionary of English v.0.48

Dissuasive \Dis*sua"sive\, a.
   Tending to dissuade or divert from a measure or purpose;
   dehortatory; as, dissuasive advice. -- n. A dissuasive
   argument or counsel; dissuasion; dehortation. --Prynne. --
   {Dis*sua"sive*ly}, adv.
   [1913 Webster]