Crowd is passionate supporting Wales at last (5)
I believe the answer is:
swarm
'crowd' is the definition.
(I know that swarm is a type of crowd)
'passionate supporting wales at last' is the wordplay.
I cannot really understand how this works, but
'passionate' could be 'warm' (I've seen this before) and 'warm' is present in the answer.
A single letter 's' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
'is' acts as a link.
Can you help me to learn more?
(Other definitions for swarm that I've seen before include "New colonists" , "Body of bees" , "some setting up colony" , "Large crowd" , "Hive" .)