Old money? Discuss at length (7)
I believe the answer is:
expound
'discuss at length' is the definition.
The answer and definition can be both to do with communicating as well as being verbs in their base form.
Perhaps there's a link between them I don't understand?
'old money?' is the wordplay.
'old' becomes 'ex'.
'money?' becomes 'pound' (I've seen this in other clues).
'ex'+'pound'='EXPOUND'
Can you help me to learn more?
(Other definitions for expound that I've seen before include "Set forth, explain in detail" , "Explain meaning in detail" , "Elucidate" , "Explain and interpret" , "Present and explain (a theory)" .)