Alternate representation of Turkestan (4,5)
I believe the answer is:
take turns
'alternate' is the definition.
(synonyms)
'representation of turkestan' is the wordplay.
'representation of' indicates an anagram (I've seen this in other clues).
'turkestan' with letters rearranged gives 'TAKE TURNS'.
(Other definitions for take turns that I've seen before include "Work on an alternating basis" , "Participate in rotation" , "Alternate" , "in sequence" , "share the driving, say" .)