1. 
[syn: cocksure, overconfident, positive]
The Collaborative International Dictionary of English v.0.48:
Cocksure \Cock"sure`\, a.
   1. Perfectly safe. [Obs.]
      [1913 Webster]
            We steal as in a castle, cocksure: . . . we walk
            invisible.                            --Shak.
      [1913 Webster]
   2. Quite certain. [Colloq.]
      [1913 Webster]
            I thought myself cocksure of the horse which he
            readily promised me.                  --Pope.
      [1913 Webster]
   3. overconfident; -- of people; as, the team was so cocksure
      of winning that they didn't practice in the week before
      the big game.. [Colloq.]
      [1913 Webster]
WordNet (r) 3.0 (2006):
cocksure
    adj 1: marked by excessive confidence; "an arrogant and cocksure
           materialist"; "so overconfident and impudent as to speak
           to the queen"; "the less he knows the more positive he
           gets" [syn: cocksure, overconfident, positive]
Moby Thesaurus II by Grady Ward, 1.0:
28 Moby Thesaurus words for "cocksure":
   arrogant, assured, certain, confident, convinced, decided,
   determined, hubristic, overconfident, oversure, overweening,
   persuaded, poised, pompous, positive, proud, reassured, secure,
   self-assured, self-confident, self-important, self-reliant, sure,
   unafraid, undoubting, unfaltering, unhesitating, unwavering