Timothy has the right to be tidy (4)
I believe the answer is:
trim
'be tidy' is the definition.
(similar in meaning)
'timothy has the right' is the wordplay.
'timothy' becomes 'tim' (I've seen this in other clues).
'has' is an insertion indicator.
'the right' becomes 'r' (common abbreviation).
'tim' enclosing 'r' is 'TRIM'.
'to' acts as a link.
(Other definitions for trim that I've seen before include "Make smooth by cutting away irregular parts" , "Cut, prune; decorate" , "Neat and tidy as a town in Meath" , "Cut off; slim and fit" , "Neat - crop" .)