One may have a nap on it (7)
I believe the answer is:
flannel
'one may' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'a nap on it' is the wordplay.
I cannot really understand how this works, but
'a' could be 'an' and 'an' is found in the answer.
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'have' acts as a link.
Can you help me to learn more?
(Other definitions for flannel that I've seen before include "used for washing face" , "Facecloth - soft soap" , "Talk evasively; cloth" , "Woollen cloth or soft soap" , "something to wash with" .)