Chap most able to support the groom (4,3)
I believe the answer is:
best man
'groom' is the definition.
The definition and answer can be both people as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'chap most able to support the' is the wordplay.
I cannot quite see how this works, but
'chap' could be 'man' (chap can mean a man) and 'man' is found in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is located in the answer.
The remaining letters 'bes' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for best man that I've seen before include "May he win!" , "Important supporting role at a wedding" , "Bloke participating in match" , "The groom's assistant at a wedding" , "The groom's right-hand supporter" .)