Aggravate former expert, getting second grade in degree (10)

I believe the answer is:

exacerbate

I'm a little stuck... Click here to teach me more about this clue!

'aggravate' is the definition.
(I know that aggravate can be written as exacerbate)

'former expert getting second grade in degree' is the wordplay.
'former' becomes 'ex' (prefix meaning former or onetime).
'expert' becomes 'ace' (ace can informally mean very good).
'getting' is a charade indicator (letters next to each other).
'second grade' becomes 'r' (and letter of 'grade').
'in degree' becomes 'bate' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'ex'+'ace'+'r'+'bate'='EXACERBATE'

Can you help me to learn more?

(Other definitions for exacerbate that I've seen before include "Provoke" , "Worsen" , "Make (a bad thing) worse" .)

I've seen this clue in The Independent.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.