Fears of thickheaded blunders? (7)

I believe the answer is:

terrors

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

'fears' is the definition.
(I know this)

'thickheaded blunders?' is the wordplay.
'thickheaded' becomes 't' (this could be a standard abbreviation I've not previously seen).
'blunders?' becomes 'errors' (blunder is a kind of error).
't'+'errors'='TERRORS'

'of' is the link.

Can you help me to learn more?

(Another definition for terrors that I've seen is " Great fears".)

I've seen this clue in the Evening Standard.

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.