Have recourse to switching the roster (6)
I believe the answer is:
resort
'have recourse to' is the definition.
(thesaurus)
'switching the roster' is the wordplay.
'switching' indicates anagramming the letters.
'roster' with letters rearranged gives 'RESORT'.
(Other definitions for resort that I've seen before include "Nice for one" , "Place many go to" , "Source of help - holiday location" , "site for recreation" , "Place for holidays" .)