No longer close match for item of sleepwear (7)
I believe the answer is:
nightie
'sleepwear' is the definition.
(I've seen this before)
'no longer close match for item' is the wordplay.
'no longer close match for' becomes 'nigh' (I can't explain this - if you can you should believe this answer much more).
'item' becomes 'tie' (I have seen 'Item of neckwear ' mean 'tie' so perhaps 'item' could also mean 'tie').
'nigh'+'tie'='NIGHTIE'
'of' is the link.
Can you help me to learn more?
(Other definitions for nightie that I've seen before include "Garment for ladies" , "worn by some retired people" , "Clothing worn in retirement?" , "Light sleeping gown" , "cover for retiring" .)