Worries that an article breaks down (8)
I believe the answer is:
feathers
'down' is the definition.
(I've seen this before)
'worries that an article breaks' is the wordplay.
'worries' becomes 'fears' (fearing is a kind of worrying).
'that an article' becomes 'the' (the definite article in English).
'breaks' indicates putting letters inside.
'fears' enclosing 'the' is 'FEATHERS'.
(Other definitions for feathers that I've seen before include "Plumage, insulation for birds" , "Bird insulation" , "growth of birds" , "Aids to flight" , "Plumages" .)