Clare wanders behind parking lot (6)
I believe the answer is:
parcel
'lot' is the definition.
(thesaurus)
'clare wanders behind parking' is the wordplay.
'wanders' indicates an anagram.
'behind' says to put letters next to each other.
'parking' becomes 'p' ().
'clare' with letters rearranged gives 'arcel'.
'arcel' after 'p' is 'PARCEL'.
(Other definitions for parcel that I've seen before include "plot" , "Pack" , "Packet" , "Piece (of land); something to post" , "Package wrapped in paper" .)