Find nothing really under layer of cartilage (9)
I believe the answer is:
discovery
'find' is the definition.
(synonyms)
'nothing really under layer of cartilage' is the wordplay.
'nothing' becomes 'O' (looks like zero - 0).
'really' becomes 'very' (I've seen this before).
'under' is a charade indicator (letters next to each other) (below, in a down clue).
'layer of cartilage' becomes 'disc' (I can't justify this - if you can you should believe this answer much more).
'o'+'very'='overy'
'overy' put after 'disc' is 'DISCOVERY'.
Can you help me to learn more?
(Other definitions for discovery that I've seen before include "Bay in southeast Australia" , "Find - Scott's ship" , "Detection, unearthing" , "Space shuttle which launched the Hubble telescope" , "Something newly found" .)