Mad character in following chapter originally goes rabbiting (10)
I believe the answer is:
chattering
'rabbiting' is the definition.
'mad character in following chapter originally goes' is the wordplay.
'mad character' becomes 'hatter' (Alice In Wonderland).
'following' says to put letters next to each other.
'chapter' becomes 'c'.
'originally' says to take the initial letters.
The first letter of 'goes' is 'g'.
'hatter'+'in'='hatterin'
'hatterin' put after 'c' is 'chatterin'.
'chatterin'+'g'='CHATTERING'
(Other definitions for chattering that I've seen before include "babbling" , "Educated people expressing views on the issues of the day" .)