You may have a nap on it (6)
I believe the answer is:
carpet
'you may' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'a nap on it' is the wordplay.
I cannot really see how this works, but
'a' is found in the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is present in the answer.
This explanation may well be incorrect...
'have' is the link.
Can you help me to learn more?
(Other definitions for carpet that I've seen before include "blanket" , "A red ...... is rolled out for VIPs" , "Dress down" , "Floor-covering" , "On the ......- getting a ticking-off" .)