Item of clothing hard to obtain close to Christmas (6)
I believe the answer is:
tights
'item of clothing hard to' is the definition.
I can't tell whether this definition defines the answer.
'close to christmas' is the wordplay.
'close' becomes 'tight' (synonyms).
'to christmas' becomes 's' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'tight'+'s'='TIGHTS'
'obtain' acts as a link.
Can you help me to learn more?
(Other definitions for tights that I've seen before include "Woman's garment" , "Item of hosiery" , "Pantihose" , "Ladies or theatrical hose" , "Ladies' hosiery" .)