Make light of dropping Penny's cushion on the floor (8)
I believe the answer is:
underlay
'floor' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe you can see an association between them that I can't see?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for underlay that I've seen before include "Lining placed beneath carpet etc" , "being initially floored" , "Felt or rubber beneath carpet" , "Carpet backing" , "Was the cause of something" .)