Thought a pupil perfect (5)

I believe the answer is:

ideal

'perfect' is the definition.
('ideal' can be similar in meaning to 'perfect')

'thought a pupil' is the wordplay.
'thought' becomes 'idea' ('idea' can be a synonym of 'thought'**).
'a pupil' becomes 'l'.
'idea'+'l'='IDEAL'

(Other definitions for ideal that I've seen before include "Best possible" , "faultless" , "Paradigm" , "Cutting/stabbing weapons" , "Perfect; a standard of perfection" .)

I've seen this clue in The Guardian and The Telegraph.

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