Demonstrated broken cane’s origin (10)
I believe the answer is:
provenance
'origin' is the definition.
(I know that provenance is a type of origin)
'demonstrated broken cane's' is the wordplay.
'demonstrated' becomes 'proven' (prove can mean to demonstrate).
'broken' is an anagram indicator.
'cane' is an anagram of 'ance'.
'proven'+'ance'='PROVENANCE'
(Other definitions for provenance that I've seen before include "Source of painting" , "Origin of" , "Documented history" .)