smart as a tack (adjective) sharp: perceptive, quick-witted
Sinonime: acute,
adroit,
alert,
apt,
astute, brainy,
bright,
brilliant,
canny,
clever,
critical,
cute,
discerning, discriminating,
fast,
foxy*, having smarts,
ingenious,
intelligent,
keen,
knowing,
nimble, nobody's fool, not born yesterday,
observant, on the ball,
original,
penetrating, penetrative,
quick, quick on the trigger, quick on the uptake,
ready,
resourceful,
savvy*,
sensitive,
slick,
smart, smart as a tack,
subtle,
wiseAntonime: ignorant,
stupid,
unintelligent