Argument following fine after this, oddly (4)
I believe the answer is:
tiff
'argument' is the definition.
(thesaurus)
'following fine after this oddly' is the wordplay.
'following' becomes 'f' (used when citing page numbers etc).
'fine' becomes 'f' (abbreviation).
'after' means one lot of letters go next to another.
'oddly' means one should take alternating letters.
The alternating letters of 'this' are 'ti'.
'f'+'f'='ff'
'ff' after 'ti' is 'TIFF'.
(Other definitions for tiff that I've seen before include "Hard to lose opening argument" , "Quarrel (colloq.)" , "pet" , "Minor argument" , "A petty quarrel or difference" .)