Opposition left off? Exactly! (5,2)
I believe the answer is:
right on
'exactly' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for right on that I've seen before include "politically correct?" , "Positive statement" , "Words of encouragement" , "Socially relevant" , "Absolutely!" .)