Shortcut Key: Del
Deletes selected entities from the drawing.
Select the entities in the drawing you want to erase. Then choose the Erase command.
Menu: Edit / Erase Last
Shortcut Key: Ctrl+E
Deletes the most recently drawn entity from the drawing.
Each subsequent time you use this command, it erases the next most recently drawn entity,working its way from last to first entity drawn in that session.
This command pays attention only to the order in which entities were drawn originally. It does not acknowledge modifications to existing entities or undo them, but erases entire entities.