Rest as site out of order (6)
I believe the answer is:
siesta
'rest' is the definition.
(thesaurus)
'as site out of order' is the wordplay.
'out of order' is an anagram indicator.
'as'+'site'='assite'
'assite' is an anagram of 'SIESTA'.
(Other definitions for siesta that I've seen before include "PM snooze" , "After lunch nap" , "Afternoon relaxation" , "Diurnal nap in Spain" , "Spanish afternoon activity" .)