Pretentious maiden, say, hit on knight (9)
I believe the answer is:
overblown
'pretentious' is the definition.
(similar in meaning)
'maiden say hit on knight' is the wordplay.
'maiden say' becomes 'over' (maiden is a kind of over).
'hit' becomes 'blow' (blow can mean a hit).
'on' means one lot of letters go next to another.
'knight' becomes 'N' (chess abbreviation).
'over'+'blow'+'n'='OVERBLOWN'
(Other definitions for overblown that I've seen before include "roses being so past their best" , "bombastic" , "Exaggerated" , "excessive" , "fifteen [POMPOUS]" .)