At setup, roll your hands open so the clubface is almost straight up. Now make a swing. The position you will feel at the top is now "Layed Off". You would have to roll your hands back to hit the ball square.

Laying off happens with a normal swing when the hands get to thinking that they need to help the face open up and close back for more power....bad for timing, bad for consistancy...just bad.

Some players will do this, just slightly, on purpose to produce a hook. They have to time it just right, but when done right, the face gets closed slightly at impact causing hook spin.