Small pet I left for schoolchild (5)

I believe the answer is:

pupil

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'for schoolchild' is the definition.
(synonyms)

'small pet i left' is the wordplay.
'small pet' becomes 'pup' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'left' becomes 'l' (common abbreviation).
'pup'+'i'+'l'='PUPIL'

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(Other definitions for pupil that I've seen before include "Schoolchild; part of eye" , "School learner" , "Learner in the eye?" , "Centre of iris, in the eye" , "Aperture in an eye" .)

I've seen this clue in The Times.

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