Deleting Objects

The simplest way to delete objects is to select them and press the Delete key.
The Clear menu also contains options for clearing (deleting) objects:
Clear Selection: Deletes all selected objects.
Clear All: Deletes all objects in the active Model Space or Paper Space. Other spaces are not affected, but using Clear All in Model Space will leave viewports in Paper Space empty.

...

Clear Constructions: Deletes all constructions or a selected construction from the drawing. In Paper Space, only constructions added in Paper Space will be deleted. See See Construction Geometry.