Male doctor ran to senior nursing officer (6)
I believe the answer is:
matron
'senior nursing officer' is the definition.
(I've seen this before)
'male doctor ran to' is the wordplay.
'male' becomes 'm' (common abbreviation).
'doctor' indicates anagramming the letters.
'ran'+'to'='ranto'
'ranto' anagrammed gives 'atron'.
'm'+'atron'='MATRON'
(Other definitions for matron that I've seen before include "Woman in charge of nurses" , "Senior nursing officer of old" , "Head of nursing" , "Medical supervisor" , "Chief nurse" .)