Behaving superciliously, finding his shoehorn gone unexpectedly (2,4,4,5)
I believe the answer is:
on ones high horse
'behaving superciliously' is the definition.
I know nothing about this answer so I cannot judge whether this works.
'his shoehorn gone unexpectedly' is the wordplay.
'unexpectedly' indicates anagramming the letters.
'his'+'shoehorn'+'gone'='hisshoehorngone'
'hisshoehorngone' anagrammed gives 'ON ONES HIGH HORSE'.
'finding' acts as a link.
Can you help me to learn more?
(Other definitions for on ones high horse that I've seen before include "in an attitude of smug superiority" , "With an air of superiority" , "like George IV in Trafalgar Square?" , "Overbearing" .)