"Fiery" saint (4)
I believe the answer is:
elmo
'fiery saint' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for elmo that I've seen before include "Fiery saint" , "St ...'s fire, weather phenomenon of coloured glow" , "Sesame Street character - patron saint of sailors (with his own fire)" , "Saint whose "fire" occurs around masts etc" , "Saint whose fire is electric!" .)