Is he superior to the groom? (4,3)
I believe the answer is:
best man
'is he superior to the groom?' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'he superior to the groom?' is the wordplay.
I cannot quite see how this works, but
'he' could be 'man' (I've seen this in another clue) and 'man' is present in the answer.
'superior' could be 'best' (associated in meaning) and 'best' is found in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for best man that I've seen before include "Supporting male actor at a wedding" , "Bridegroom's mate" , "Important supporting role at a wedding" , "Groom's friend" , "Bridegroom's friend" .)