As verbs the difference between overlay and rug
is that
overlay is to lay, or spread, something over or across; to cover while
rug is to pull roughly or hastily; to plunder; to spoil; to tear.
As nouns the difference between overlay and rug
is that
overlay is a piece of paper pasted upon the tympan sheet to improve the impression by making it stronger at a particular place while
rug is a partial covering for a floor.