Such boys still have some schooldays! (3)
I believe the answer is:
old
'such boys still' is the definition.
Both the definition and answer are adjectives. Perhaps there's a link between them I don't understand?
'some schooldays' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'OLD' is hidden within '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" .)