One disposing of wine collection, did you hear? (6)
I believe the answer is:
seller
'one disposing of wine collection did you hear?' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
This is the entire clue.
Can you help me to learn more?
(Other definitions for seller that I've seen before include "One who disposes of" , "Person making sale" , "Resell to vendor" , "Trader" .)