[Date: 1400-1500; Origin: balk 'raised area that gets in the way of forward movement' (15-21 centuries), from Old English balca 'pile of things on the ground']
to not want to do or try something, because it seems difficult, unpleasant, or frightening
Many people would balk at setting up a new business during a recession.
Westerners balk at the prospect of snake on the menu.
if a horse balks at a fence, it stops in front of it and refuses to jump over it
in baseball, to stop in the middle of the action of throwing the ball to the player who is trying to hit it
to stop someone or something from getting or achieving what they want