I'm cast wrongly as organic glue (6)
I believe the answer is:
mastic
'organic glue' is the definition.
The definition and answer can be both substances as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'i'm cast wrongly' is the wordplay.
'wrongly' indicates anagramming the letters.
'im'+'cast'='imcast'
'imcast' with letters rearranged gives 'MASTIC'.
'as' acts as a link.
Can you help me to learn more?
(Other definitions for mastic that I've seen before include "liquor" , "Mouldable cement" , "Resin used in varnishes" , "Aromatic resin used to make varnish" , "Gum from trees" .)