Her spouse died fighting Green about wives keeping pledge? (3,5)

'pledge?' is the definition.
The answer and definition can be both people as well as being singular nouns.
Maybe you can see a link between them that I don't see?

'her spouse died fighting green about wives' is the wordplay.
I cannot quite see how this works, but
'died' could be 'd' (abbreviation next to the year of someone's death) and 'd' is found within the answer.
'fighting' could be 'war' and 'war' is found in the answer.
This explanation may well be incorrect...

'keeping' acts as a link.

Can you help me to learn more?