Overconfidence

(n.) Excessive confidence; too great reliance or trust.

Thesaurus Entries

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