Secure some land a simpleton turned for a Venetian official's wife (9)

'a venetian official's wife' is the definition.
I don't know anything about this answer so I cannot tell whether this works.

'secure some land a simpleton turned' is the wordplay.
'secure' becomes 'dog' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'some land' becomes 'are' (historical unit of measurement - d00 square metres).
'a simpleton' becomes 'ass' (ass is a kind of simpleton).
'turned' says the letters should be written backwards.
'ass' back-to-front is 'ssa'.
'dog'+'are'+'ssa'='DOGARESSA'

'for' is the link.

Can you help me to learn more?