Sailor's patron saint (4)
I believe the answer is:
elmo
'sailor's patron 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 "Saint whose fire is electric!" , "Puppet character" , "St ...'s fire, weather phenomenon of coloured glow" , "Fiery saint" , "Saint associated with fire" .)