1balk also Brit baulk 
/ˈbɑ:k/ verb
balks; balked; balk·ing /ˈbɑ:k/ verb [no obj] 1 : to suddenly show that you do not want to do something : to refuse to do what someone else wants you to do
▪ If this witness balks [=refuses to cooperate in court], our lawyers will not have enough evidence to win the case. — often + at ▪ The public balked at the President's new tax plan. ▪ He balks at sending his children to expensive private schools. [=he won't send his children to expensive private schools] 2 a of a horse, mule, etc. : to stop quickly and refuse to continue going
▪ The horse balked and would not jump the fence.
b of an engine : to fail to work in the usual or expected way
▪ I turned the key, but the car's engine balked. [=refused to start] 3 baseball, of a pitcher : to stop suddenly after starting to throw a pitch : to commit a balk
▪ The runner on third base tried to make the pitcher balk.
▪ If this witness balks [=refuses to cooperate in court], our lawyers will not have enough evidence to win the case. — often + at ▪ The public balked at the President's new tax plan. ▪ He balks at sending his children to expensive private schools. [=he won't send his children to expensive private schools]
▪ The horse balked and would not jump the fence.
b of an engine : to fail to work in the usual or expected way
▪ I turned the key, but the car's engine balked. [=refused to start]
▪ The runner on third base tried to make the pitcher balk.
