Claim a person has plan (3)
I believe the answer is:
map
'plan' is the definition.
(I've seen this before)
'claim a person has' is the wordplay.
'has' indicates the answer is hidden within the clue.
'MAP' is hidden within 'claim a person'.
(Other definitions for map that I've seen before include "Geographical plan" , "Sketch" , "face" , "(Make a) geographical representation" , "Representation of earth's surface as a guide" .)