Such boys still have some schooldays! (3)
I believe the answer is:
old
'such boys still' is the definition.
Both the answer and definition are adjectives. Perhaps there's an association between them I don't understand?
'some schooldays' is the wordplay.
'some' says the answer is hidden in the clue (some parts of the word are used).
'OLD' can be found hidden inside 'schooldays'.
'have' acts as a link.
Can you help me to learn more?
(Other definitions for old that I've seen before include "Venerable" , "At an early stage - at a late stage" , "Much-used" , "Long-lived" , "Senescent" .)