Bigheadedness, energy and drive associated with male model standing up (7)
I believe the answer is:
egotism
'bigheadedness' is the definition.
(being bigheaded is being egotistical)
'associated with male model standing up' is the wordplay.
'associated with' becomes 'ego' (I can't justify this - if you can you should give a lot more credence to this answer).
'male' becomes 'm' (common abbreviation).
'model' becomes 'sit' (e.g. for a painting).
'standing up' is a reversal indicator (in a down clue up is reverse order).
'm'+'sit'='msit'
'msit' written backwards gives 'tism'.
'ego'+'tism'='EGOTISM'
'energy and drive' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
(Other definitions for egotism that I've seen before include "Obsession with oneself" , "Self-love" , "Selfishness" , "Self-obsession" , "Items go (anag.)" .)