The title Wastwater Screes applies to the scree-covered north-western fellside which plunges dramatically down into Wastwater. This also includes Illgill Head's neighbour Whin Rigg, the continuation of the ridge to the south-west.
The term "Wastwater Screes" designates the steep, scree-covered northern side of the fell which plunges down towards Wastwater.  This area includes Illgill Head's neighboring hill, Whin Rigg, and extends southward along the ridge.