It's of some material, possibly protective (3)
I believe the answer is:
mat
'protective' is the definition.
Both the answer and definition are adjectives. Maybe they are linked in a way I don't understand?
'it's of some material' is the wordplay.
'it' becomes 'm' (I am not sure about this - if you are sure you should believe this answer much more).
'of some' says to take the centre (I've seen 'some' mean this).
'material' becomes 'pleather' (type of imitation leather).
The centre of 'pleather' is 'at'.
'm'+'at'='MAT'
'possibly' acts as a link.
Can you help me to learn more?
(Other definitions for mat that I've seen before include "Floor-pad" , "carpeting" , "Opening of good book" , "Rug; without a shine" , "Paint with a dull surface" .)