Crazy about ... about ... about vision (5)
I believe the answer is:
dream
'vision' is the definition.
(dream is a kind of vision)
'crazy about about about' is the wordplay.
'crazy about' becomes 'dam' (I can't justify this - if you can you should believe this answer much more).
'about' is an insertion indicator.
'about' becomes 're' ('re' means regarding or about).
'dam' placed around 're' is 'DREAM'.
Can you help me to learn more?
(Other definitions for dream that I've seen before include "Cherished hope; fantasy" , "Illusion" , "Part of sleep" , "Aspiration" , "Aspire" .)