Tell's apple, brief hazard for lad's crown (7)
I believe the answer is:
apprise
'tell's' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for apprise that I've seen before include "Tell, advise" , "Give information to" , "Inform or tell" , "Provide with information" , "tip off" .)