Wallow in humour (7)
I believe the answer is:
indulge
I believe this clue is a double definition.
'wallow in' is the first definition.
(thesaurus)
'humour' is the second definition.
(I know that humour is a more specific form of indulge)
(Other definitions for indulge that I've seen before include "Satisfy (a desire)" , "Pamper, spoil" , "Spoil - oneself, maybe" , "take to the drink?" , "Allow person to have what he/she wishes" .)