(a.) Having an overweening opinion of one's own powers, attainments; vain; conceited.

aggressively self-confident bluff bold brash bumptious cheeky chesty chutzpadik cocky conceited contemptuous crusty derisive disrespectful facy flip flippant forward fresh gally gratuitous immodest impertinent impudent know-it-all malapert nervy obtrusive overwise peacockish peacocky perk perky pert procacious puffed up rude sassy saucy self-conceited self-opinionated smart smart-alecky smart-ass stuck-up swelled-headed uncalled-for wise-ass