Branding sheep raised by royal (7)
I believe the answer is:
marking
'branding' is the definition.
('mark' can be a synonym of 'brand')
'sheep raised by royal' is the wordplay.
'sheep' becomes 'ram' (male sheep).
'raised by' says the letters should be written backwards.
'royal' becomes 'king' (a king is royal).
'ram' back-to-front is 'mar'.
'mar'+'king'='MARKING'
(Other definitions for marking that I've seen before include "assessment" , "Staying close to an opposing player" , "Becoming stained" , "Labelling" , "Rating (school work)" .)