Crossword Genius

Explained past partner got punched (9)

Ross

I believe the answer is:

expounded

I'm a little stuck... Click here to teach me more about this clue!

'explained' is the definition.
(I've seen this before)

'past partner got punched' is the wordplay.
I cannot quite understand how this works, but
'past' could be 'ex' (similar in meaning) and 'ex' is found in the answer.
'partner' could be 'n' and 'n' is present in the answer.
This explanation may well be incorrect...

Can you help me to learn more?

(Other definitions for expounded that I've seen before include "commented on" , "Explained" , "made clear" .)

I've seen this clue in the Sydney Morning Herald.
Want a hint initially instead of a full solution? Install my app