A doctor got up for this chap (7)
I believe the answer is:
ambrose
'this chap' is the definition.
'a doctor got up' is the wordplay.
'doctor' becomes 'MB' (Bachelor of Medicine, Medicinae Baccalaureus).
'got up' becomes 'rose' (past tense of 'raise').
'a'+'mb'+'rose'='AMBROSE'
'for' acts as a link.
(Other definitions for ambrose that I've seen before include "Curtly perhaps" , "name" , "Early saint; - Bierce, author" , "Bishop-saint" , "saint, maybe" .)