Underside recess either cut or molded into an object so as to leave a topside lip or protuberance.

1. An unfilled groove melted into the base metal at the toe of a weld.

2. To fail to machine a part to a sufficient extent.

To cut below or in the lower part of a coal bed by chipping away the coal with a pick or mining machine; cutting is usually done on the level of the floor of the mine, extending laterally the entire face and 5 or 6 feet (1.5 or 1.8 meters) into the material.