Excessive ego of one pursuing maiden? (14)
I believe the answer is:
overconfidence
'excessive ego' is the definition.
(an overconfident person is egotistical)
'of one pursuing maiden?' is the wordplay.
I cannot really understand how this works, but
'of' could be 'o' and 'o' is found in the answer.
'one' could be 'er' (I've seen this in other clues) and 'er' is present in the answer.
This may be the basis of clue (or it may be nonsense).
(Other definitions for overconfidence that I've seen before include "Excessive self-assurance" , "An excess of self-assurance" .)