as sharp as a tack
Quick on uptake
As sharp as a tack describes someone who is mentally quick, alert, and perceptive.
The comparison is to a tack's fine point, though the phrase almost always refers to wit rather than physical sharpness: My grandmother is ninety-two and still sharp as a tack.
Often shortened to sharp as a tack.
Showing mental quickness
- quick-wittedFast at thinking
- astuteMentally sharp, discerning
- shrewdPractically clever, perceptive
- perceptiveQuick to understand
brilliant · keen · smart · bright · alert · savvy · on the ball · quick
Paying close notice
- vigilantKeenly aware of danger
- awareHaving knowledge of
- focusedDirecting attention narrowly
- clearheadedMentally focused and rational
lucid · responsive · observant · watchful · awake · present · on point · engaged
Higher in rank
- octogenarianPerson in ninth decade
- nonagenarianPerson aged ninety-plus
- centenarianPerson over ninety-nine
- grandmotherMother of a parent
grandfather · elder · retiree · old-timer · aging · vital · spry
clever
Showing mental quickness
- quick-wittedFast at thinking
- astuteMentally sharp, discerning
- shrewdPractically clever, perceptive
perceptive · brilliant · keen · smart · bright · alert · savvy · on the ball · quick · discerning
attentive
Paying close notice
clearheaded · lucid · responsive · observant · watchful · awake · present · on point · engaged · ready
senior
Higher in rank
- octogenarianPerson in ninth decade
- nonagenarianPerson aged ninety-plus
- centenarianPerson over ninety-nine
grandmother · grandfather · elder · retiree · old-timer · aging · vital · spry
as sharp as a tackslow on the uptake
Comprehending things belatedly
thick as a brick · dumb as a box of rocks · dull · dumb as a post · dense
sharp, tack, tackle, sharpen, sharper, sharpness, sharply, sharpening, sharpened