Pert, following kiss (4)
I believe the answer is:
flip
'pert' is the definition.
(thesaurus)
'following kiss' is the wordplay.
'following' becomes 'f.' (used when citing page numbers etc).
'kiss' becomes 'lip' (I've seen this in other clues).
'f'+'lip'='FLIP'
(Other definitions for flip that I've seen before include "Turn (over) - impudent" , "Go mad" , "Propel with finger - lose one's temper" , "Throw a wobbly" , "See red" .)