Cracked up, oddly enough (6,4)
I believe the answer is:
broken down
'enough' is the definition.
Both the definition and answer are adjectives. Maybe you can see a link between them that I don't see?
'cracked up oddly' is the wordplay.
'cracked' becomes 'broken' (similar in meaning).
'up oddly' becomes 'down' (I can't justify this - if you can you should give a lot more credence to this answer).
'broken'+'down'='BROKEN-DOWN'
Can you help me to learn more?
(Other definitions for broken down that I've seen before include "Analysed" , "worn out" .)