Don't enumerate so much, it's dull (8)
I believe the answer is:
listless
'dull' is the definition.
(thesaurus)
'don't enumerate so much it's' is the wordplay.
I cannot really see how this works, but
'enumerate' could be 'list' (listing is a kind of enumerating) and 'list' is located in the answer.
'it's' could be 'es' ('e' can mean 'electronic' which is similar to 'IT') and 'es' is present in the answer.
This may be the basis of clue (or it may be nonsense).
(Other definitions for listless that I've seen before include "Lacking zest or enthusiasm" , "Lacking energy or interest" , "disorganised on a shopping trip?" , "'Lethargic, spiritless (8)'" , "Showing no enthusiasm, torpid" .)