Quashes charge brought by new partner (7)
I believe the answer is:
stepson
'partner' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps there's an association between them I don't understand?
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for stepson that I've seen before include "Spouse's child from previous marriage" , "Child of a spouse by a former marriage" , "Child from a spouse's former marriage" , "younger member of family" , "could be issue for partner" .)