overconfident (adj.)
- arrogant
- assured
- audacious
- brash
- brazen
- cocksure
- cocky
- confident
- convinced
- decided
- determined
- foolhardy
- hasty
- heedless
- improvident
- imprudent
- impudent
- incautious
- indiscreet
- injudicious
- insolent
- overbearing
- overbold
- overweening
- persuaded
- poised
- pompous
- positive
- proud
- pushful
- pushy
- rash
- reassured
- secure
- self-assertive
- self-assured
- self-confident
- self-important
- self-reliant
- sure
- swaggering
- temerarious
- thoughtless
- unafraid
- unfaltering
- unhesitating
- unwary
- unwavering
- uppity
- vainglorious
