Satisfaction guaranteed following appeal (8)
I believe the answer is:
pleasure
'satisfaction' is the definition.
(I've seen this in another clue)
'guaranteed following appeal' is the wordplay.
'guaranteed' becomes 'sure' (I've seen this in other clues).
'following' means one lot of letters go next to another.
'appeal' becomes 'plea' (plea is a kind of appeal).
'sure' put after 'plea' is 'PLEASURE'.
(Other definitions for pleasure that I've seen before include "Enjoyment, happiness" , "Gratification of the senses" , "entertainment" , "Delectation, delight" , "'Enjoyment, delight (8)'" .)