Superior companion harbours yen for lofty dwelling (5)
I believe the answer is:
eyrie
'lofty dwelling' is the definition.
(I've seen this before)
'superior companion harbours yen' is the wordplay.
'superior companion' becomes 'erie' (I've seen this before).
'harbours' means one lot of letters goes inside another (harbour can mean to hide or give shelter to).
'yen' becomes 'y' (resembles the symbol for the currency of Japan).
'erie' enclosing 'y' is 'EYRIE'.
'for' acts as a link.
(Other definitions for eyrie that I've seen before include "highly placed house" , "Eagle nest" , "place for the high and mighty" , "lofty house" , "High altitude habitation" .)