Skin filled veneer designed to gather again (9)
I believe the answer is:
reconvene
'gather again' is the definition.
('convene' is an answer for 'gather' so perhaps 'reconvene' is OK for 'gather again')
'skin filled veneer designed' is the wordplay.
'skin' becomes 'con' (I can't justify this - if you can you should give a lot more credence to this answer).
'filled' is an insertion indicator.
'designed' indicates an anagram (designed with the letters).
'veneer' with letters rearranged gives 'revene'.
'con' placed within 'revene' is 'RECONVENE'.
'to' is the link.
Can you help me to learn more?
(Other definitions for reconvene that I've seen before include "Meet again" , "get together again" .)