Hibernating snake wrapped around shelter (6)
I believe the answer is:
asleep
'hibernating' is the definition.
(similar in meaning)
'snake wrapped around shelter' is the wordplay.
'snake' becomes 'asp' (asp is a kind of snake).
'wrapped around' means one lot of letters goes inside another.
'shelter' becomes 'lee' (as in lee side, the side sheltered from wind).
'asp' going around 'lee' is 'ASLEEP'.
(Other definitions for asleep that I've seen before include "Napping" , "(Of a limb) numb" , "like a kipper" , "In the arms fo Morpheus" , "coiled up?" .)