Bring up to be stern (4)
I believe the answer is:
rear
This clue is a triple definition!
'bring' is the first definition.
(thesaurus)
'up' is the second definition.
(thesaurus)
'to be' acts as a link.
'stern' is the third definition.
('rear' can be a synonym of 'stern')
(Other definitions for rear that I've seen before include "Hind part" , "Hitchcock film set in one room" , "Posterior" , "what you may bring up" , "Jump" .)