noun

1. a ridge of unplowed land between furrows
2. a roughly hewn piece of timber
3. a beam used in construction
4. something that obstructs or thwarts; check, hindrance, disappointment, etc.
5. Obsolete a blunder; error
6. Baseball an illegal motion by the pitcher, such as an uncompleted motion to throw to a base, while one foot is on the rubber: it entitles each base runner to advance one base
7. Billiards any of the outer spaces between the cushions and the balkline

Etymology: ME balke < OE balca, a bank, ridge < IE *bhelg- (extended stem of *bhel-, a beam) > Ger balken, beam, Gr phalanx, L fulcrum

transitive verb

1. Obsolete to make balks in (land)
2. to obstruct or thwart; foil
3. Archaic to miss or let slip by
4. Baseball to force (a base runner to score from third base) by committing a balk

intransitive verb

1. to stop and obstinately refuse to move or act
2. to hesitate or recoil (at)
3. to make a balk in baseball