Habitual sunbather in Cornish coastal area (6)
I believe the answer is:
lizard
I believe this is a double definition.
'habitual sunbather' is the first definition.
(lizards sunbathe)
'cornish coastal area' is the second definition.
(as in Lizard Point in Cornwall)
'in' acts as a link.
(Other definitions for lizard that I've seen before include "Four-legged reptile" , "A reptile; a Cornish Head" , "Long reptile with two legs" , "Chameleon, perhaps" , "leading to a windswept village" .)