It is an old saying meaning that the person is sharp, or very intelligent.
Tack
A trimmers hammer was used to upholster car interiors in the early 1900's. The hammer had two long tapered heads, the smaller head was magnetized to hold the tack, the larger head was used to drive the tack home
Tack
biskits
to smoke tack is to smoke cannabis resin i.e marijuana plant substitute
It's actually "tak" and it means "yes" ;-).
tack så mycket means thank you very much, or thanks a lot.
'Thanks'. Tack is pronounced tahk.
Low coolant warning
it come from the sharpest tack of the world
Nope - it's a short sound - like back, sack and rack. Not a long sound like rake, take or bake
A horse can throw it's head back no matter what piece of tack is used if it's determined to do it. But many people use a martingale to keep a horses head down, though this is not a good substitute for real training of the horse.