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 am not sure about this - if you are sure you should give a lot more credence to this answer).
'item' becomes 'tie' (I have seen 'Item of neckwear ' mean 'tie' so perhaps 'item' could also mean 'tie').
'nigh'+'tie'='NIGHTIE'
'of' acts as a 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" .)