Balk

A balk of timber is a beam running across the ceiling, etc., like a ridge. As the balk is the part not cut by the plough, therefore “to balk” means to leave untouched, or to disappoint.

To make a balk. To miss a part of the field in ploughing. Hence to disappoint. to withhold deceitfully.

To make a balk of good ground. To throw away a good chance.