I’m left unusual cane showing value (10)
I believe the answer is:
importance
'value' is the definition.
(I know that importance is a type of value)
'i'm left unusual cane' is the wordplay.
'left' becomes 'port' (left side of a ship - opposite of starboard).
'unusual' is an anagram indicator.
'cane' anagrammed gives 'ance'.
'im'+'port'+'ance'='IMPORTANCE'
'showing' is the link.
(Other definitions for importance that I've seen before include "standing" , "moment" , "See 6" , "Mark" , "value" .)