Like something of yours or mine that's crazy (9)
I believe the answer is:
possessed
'that's crazy' is the definition.
(thesaurus)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for possessed that I've seen before include "Bore" , "being mad?" , "controlled by inner demons?" , "Demented" , "in need of bell, book and candle" .)