Bring up the back (4)
I believe the answer is:
Here is my best explanation:
I believe this is a triple definition!
'bring' is the first definition.
'up' is the second definition.
'the back' is the third definition.
('rear' can be a synonym of 'back')
(Other definitions for rear that I've seen before include "Bring up and care for", "Bring up (children)", "Raise; behind", "Back; bring up (young)", "Hindmost part", "Bring up - the tail", "Buttocks - rise up", "Rump", "Back end" and "It's rare at the back".)