Metal in half-finished state (3)
I believe the answer is:
ore
'metal' is the definition.
(I have seen 'Raw metal ' mean 'ore' so perhaps 'metal' could also mean 'ore')
'half-finished state' is the wordplay.
'half-finished' means to take half the letters.
'state' becomes 'oregon' (Oregon is an example).
'oregon' halved is 'ORE'.
'in' acts as a link.
(Other definitions for ore that I've seen before include "Mineral-bearing material" , "Danish currency" , "Foreign currency" , "Mineral-bearing rock" , "It's mined for minerals" .)