Phobia about the quill (7)
I believe the answer is:
feather
'quill' is the definition.
(I've seen this before)
'phobia about the' is the wordplay.
'phobia' becomes 'fear' (I've seen this in another clue).
'about' indicates putting letters inside.
'fear' enclosing 'the' is 'FEATHER'.
(Other definitions for feather that I've seen before include "manipulate oar" , "The fear (anag) - type of bed" , "Wing component" , "One of a bird's waterproof covering" , "Prov. light part of bird" .)