He will knock lots down for people to pick up (10)
I believe the answer is:
auctioneer
This might be a double definition.
'he will knock lots down for people' is the first definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'pick up' is the second definition.
The definition and answer can be both to do with ownership as well as being verbs in their base form.
Perhaps they are linked in a way I don't understand?
'to' is the link.
Can you help me to learn more?
(Other definitions for auctioneer that I've seen before include "one that has lots to offer" , "One selling lots" , "One inviting bids for lots" .)