Right to get one doctor a pin (5)
I believe the answer is:
rivet
'a pin' is the definition.
(I know that rivet is a type of pin)
'right to get one doctor' is the wordplay.
'right' becomes 'r' (common abbreviation).
'to get' says to put letters next to each other.
'one' becomes 'I' (Roman numeral).
'doctor' becomes 'vet' (vetting is a kind of doctoring).
'r'+'i'+'vet'='RIVET'
(Other definitions for rivet that I've seen before include "Captivate" , "Metal bolt that's hammered" , "Type of fastening" , "Trevi (anag.)" , "Metal fastening pin" .)