overconfidence

from WordNet (r) 3.0 (2006)

overconfidence
    n 1: total certainty or greater certainty than circumstances
         warrant [syn: {certitude}, {cocksureness},
         {overconfidence}]

from The Collaborative International Dictionary of English v.0.48

Overconfidence \O"ver*con"fi*dence\, n.
   Excessive confidence; too great reliance or trust.
   [1913 Webster]

from Moby Thesaurus II by Grady Ward, 1.0

49 Moby Thesaurus words for "overconfidence":
      arrogance, assurance, assuredness, belief, brashness, brass,
      brazen boldness, certitude, cheek, chutzpah, cocksureness,
      confidence, confidentness, conviction, courage, faith, gall,
      heroics, hubris, improvidence, imprudence, impudence, indiscretion,
      injudiciousness, insolence, overboldness, overcarelessness,
      oversureness, overweening, overweeningness, poise, pomposity,
      positiveness, pride, rashness, security, self-assurance,
      self-confidence, self-importance, self-reliance, settled belief,
      subjective certainty, sureness, surety, temerariousness, temerity,
      trust, unchariness, unwariness