Hostile to comics' vacuous buffoonery (6)
I believe the answer is:
antics
'buffoonery' is the definition.
(both can mean silly behaviour)
'hostile to comics' vacuous' is the wordplay.
'hostile to' becomes 'anti' (anti means hostile to or opposed to).
'vacuous' means to remove the middle letters.
'comics' with its centre removed is 'cs'.
'anti'+'cs'='ANTICS'
(Other definitions for antics that I've seen before include "Movements intended to be amusing, pranks" , "Absurd tricks or pranks" , "extraordinary goings-on" , "Funny movements and foolish behaviour" , "Goings-on, absurd behaviour" .)