How to correct a terribly bad issue (8)

I believe the answer is:

disabuse

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

'how to correct a' is the definition.
I can't judge whether this definition defines the answer.

'terribly bad issue' is the wordplay.
'terribly' is an anagram indicator.
'bad'+'issue'='badissue'
'badissue' is an anagram of 'DISABUSE'.

Can you help me to learn more?

(Other definitions for disabuse that I've seen before include "put right" , "Rid someone (of a mistaken idea)" , "Free from a false idea" , "Free somebody from an erroneous belief" , "Give correction to" .)

I've seen this clue in the Sydney Morning Herald.

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.