Wife is queen, being more intelligent (5)
I believe the answer is:
wiser
'more intelligent' is the definition.
'wife is queen' is the wordplay.
'wife' becomes 'w' (abbreviation).
'queen' becomes 'ER' (abbreviation for Elizabeth Regina).
'w'+'is'+'er'='WISER'
'being' acts as a link.
(Other definitions for wiser that I've seen before include "More sagacious" , "More judicious" , "A little more sage" , "More sensible" , "More prudent" .)