Dry form of humour gets her (6)
I believe the answer is:
wither
'dry' is the definition.
(thesaurus)
'form of humour gets her' is the wordplay.
'form of humour' becomes 'wit' (I've seen this before).
'gets' is a charade indicator (letters next to each other).
'wit'+'her'='WITHER'
(Other definitions for wither that I've seen before include "Dry up and perish" , "Shrivel and decay" , "Droop, shrivel" , "Shrink, shrivel up" , "Shrivel away" .)