Are embarrassed all round when it’s brought up (6)
I believe the answer is:
Here is my best explanation:
'it's brought up' is the definition.
(rearing is a kind of bringing up)
'are embarrassed all round' is the wordplay.
'embarrassed' becomes 'red' (I've seen this before).
'all round' indicates putting letters inside.
'are' going into 'red' is 'REARED'.
'when' is the link.
(Other definitions for reared that I've seen before include "upright", "Fostered, brought up", "Provided and cared for during childhood", "Brought up, nurtured", "Trained", "Raised" and "Nurtured - rose on hind legs".)