First time terrorist's abandoned wrong opinion (5)

I believe the answer is:

error

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

'first time terrorist's abandoned' is the definition.
I can't judge whether this defines the answer.

'wrong opinion' is the wordplay.
'wrong' becomes 'err'.
'opinion' becomes 'or' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'err'+'or'='ERROR'

Can you help me to learn more?

(Other definitions for error that I've seen before include "Mistake or fault" , "Miscalculation" , "A mistake or inaccuracy" , "Faulty judgment" , "Gaffe" .)

I've seen this clue in The Independent.

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