Concerns pinning article down (8)
I believe the answer is:
feathers
'down' is the definition.
(down can mean bird feathers)
'concerns pinning article' is the wordplay.
'concerns' becomes 'fears' ('fear' can be a synonym of 'concern').
'pinning' means one lot of letters goes inside another.
'article' becomes 'the' (the definite article in English).
'fears' enclosing 'the' is 'FEATHERS'.
(Other definitions for feathers that I've seen before include "''Hope is the thing with ...'' (Emily Dickinson)" , "Coverings of birds' bodies" , "growth of birds" , "Plumage, insulation for birds" , "Covering for birds" .)