Rest as site’s revamped (6)
I believe the answer is:
siesta
'rest' is the definition.
(thesaurus)
'as site's revamped' is the wordplay.
'revamped' is an anagram indicator.
'as'+'site'='assite'
'assite' with letters rearranged gives 'SIESTA'.
(Other definitions for siesta that I've seen before include "Spanish afternoon activity" , "Forty winks" , "Afternoon nap in a warm climate" , "A Spanish mid-day nap" , "Diurnal nap in Spain" .)