On paper, males aren’t ultimately essential (11)

I believe the answer is:

requirement

'essential' is the definition.
(synonyms)

'on paper males aren't ultimately' is the wordplay.
'on' becomes 're' ('on' can be mean 'with reference to').
'paper' becomes 'quire' (paper measurement).
'males' becomes 'men' (man is a kind of male).
'ultimately' suggests the final letters.
The last letter of 'arent' is 't'.
're'+'quire'+'men'+'t'='REQUIREMENT'

(Another definition for requirement that I've seen is " Necessity".)

I've seen this clue in The Times.

Want a hint initially instead of a full solution? Install my app