What does the term balk mean in baseball?

Answer:
I am referring to a pitchers balk.

There are some illegal moves that a pitcher can not do after he gets in position. Usually some sort of incorrect movement of the hands. But, balks are very rare. If one occurs, everyone moves up a base.
First answer by Gisher67. Last edit by Gisher67. Contributor trust: 0 [recommend contributor recommended]. Question popularity: 2 [recommend question].