Luxuriate (4)
I believe the answer is:
bask
'luxuriate' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for bask that I've seen before include "revel" , "Sunbathe" , "Lie in the sun" , "Lie in warmth" , "Sun oneself (like a kind of shark?)" .)