Lots in work welcoming union (7)
I believe the answer is:
auction
'lots' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'work welcoming union' is the wordplay.
I cannot really see how this works, but
'union' could be 'u' (common abbreviation as in Trades Union Congress) and 'u' is found within the answer.
'work' could be 'act' (synonyms) and 'act' is found within the leftover letters.
The remaining letters 'ion' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'in' acts as a link.
Can you help me to learn more?
(Other definitions for auction that I've seen before include "Selling" , "Where things are sold to the highest bidder" , "Caution about method of sale" , "event with lots involved" , "Use caution at public sale" .)