Opinions of the size of properties without one male (9)
I believe the answer is:
estimates
'opinions of the size' is the definition.
The definition and answer can be both acts as well as being plural nouns.
Perhaps they are linked in a way I don't understand?
'properties without one male' is the wordplay.
'properties' becomes 'estates' (estate is a kind of property).
'without' means one lot of letters goes inside another ('without' can be similar in meaning to 'outside').
'one' becomes 'I' (Roman numeral).
'male' becomes 'm' (common abbreviation).
'i'+'m'='im'
'estates' going around 'im' is 'ESTIMATES'.
'of' acts as a link.
Can you help me to learn more?
(Another definition for estimates that I've seen is " judges".)