A blow in the side? (5)
I believe the answer is:
right
'the side?' is the definition.
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for right that I've seen before include "Correct; proper" , "Authority - one hand" , "Prerogative" , "Correct; political wing" , "Privy Councillors are so honourable" .)