Fashionable substitute for wood or metal (7)
I believe the answer is:
plastic
'fashionable substitute for wood' is the definition.
The answer and definition can be both substances as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'metal' is the wordplay.
I cannot quite see how this works, but
'metal' could be 'ti' (Ti is an example) and 'ti' is located in the answer.
This explanation may well be incorrect...
'or' acts as a link.
Can you help me to learn more?
(Other definitions for plastic that I've seen before include "Capable of being moulded" , "Credit card; mouldable" , "Credit card - pliable" , "Mouldable material" , "Flexible - synthetic material" .)