What is a Butcher-Boy single in baseball?

Answer 1

It's when you square around to bunt, but then bring the bat back and swing away.

Typically used to try and punch the ball to the infield area just vacated by the defense who has players moving in response to the bunt attempt. Since the runners are on the move during a bunt attempt, they can frequently move up 2 bases if the butcher boy swing is succesful in driving the ball into the shallow outfield. It is definitelly different than a Baltimore chop.