Young child, learner seen around a comprehensive (5)
I believe the answer is:
total
'comprehensive' is the definition.
(I know that comprehensive can be written as total)
'young child learner seen around a' is the wordplay.
'young child' becomes 'tot' (tot can mean a baby or toddler).
'learner' becomes 'l' (as in a learner driver with L-plates on their car).
'seen around' indicates putting letters inside.
'tot'+'l'='totl'
'totl' placed around 'a' is 'TOTAL'.
(Other definitions for total that I've seen before include "Entire sum" , "Aggregate amount" , "Count" , "It might be grand" , "Complete, entire amount" .)