smart guy (adjective) cocky/cocksure: self-assured, full of oneself
Sinonime: arrogant,
brash, bumptious,
certain,
conceited,
confident,
egotistical, hotdogging, hotshot, hubristic, know-it-all, lordly, nervy, overconfident, overweening,
positive,
presumptuous, self-confident, smart aleck, smart guy, smarty, smarty pants,
sure, swaggering, swollen-headed,
vain, wise guy
Antonime: humble,
modest,
uncertain, unself-confident,
unsure