Old writer in problem about anthology (7)
I believe the answer is:
omnibus
'anthology' is the definition.
(I know that omnibus is a type of anthology)
'old writer in problem' is the wordplay.
'old' becomes 'o' (abbreviation).
'writer' becomes 'nib' (something which writes).
'in' is an insertion indicator.
'problem' becomes 'mus' (I can't explain this - if you can you should give a lot more credence to this answer).
'nib' going inside 'mus' is 'mnibus'.
'o'+'mnibus'='OMNIBUS'
'about' is the link.
Can you help me to learn more?
(Other definitions for omnibus that I've seen before include "Carrier" , "Collection of books reprinted in one volume" , "traffic" , "One can expect to be moved by this" , "Large volume; means of transport" .)