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