Pretentiousness by extremely attractive miss (3,4)
I believe the answer is:
air shot
'miss' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.
'pretentiousness by extremely attractive' is the wordplay.
'pretentiousness' becomes 'airs' (I've seen this before).
'by' says to put letters next to each other.
'extremely attractive' becomes 'hot' (I am not sure about the 'extremely' bit.).
'airs'+'hot'='AIR SHOT'
Can you help me to learn more?
(Another definition for air shot that I've seen is " Golf stroke that misses the ball".)