Warm, feathery layer for barbarian (7)
I believe the answer is:
heathen
'for barbarian' is the definition.
(thesaurus)
'warm feathery layer' is the wordplay.
'warm' becomes 'heat'.
'feathery layer' becomes 'hen' (feathered bird which lays eggs).
'heat'+'hen'='HEATHEN'
(Other definitions for heathen that I've seen before include "Non-believer" , "Infidel, pagan" , "Barbaric" , "Godless person" , "One who doesn't acknowledge your god" .)