(usu + at) to stop short and refuse to proceed

(often + at) to refuse abruptly

They balked at the suggestion

to check or stop (somebody or something) by an obstacle; to thwart (somebody or something)

a ridge of land left unploughed

a roughly squared beam of timber

the area behind the balk lines on a billiard table

a hindrance or obstacle

in baseball, an illegal movement by the pitcher