Suit certain to delight (8)
I believe the answer is:
pleasure
'delight' is the definition.
(I know that delight can be written as pleasure)
'suit certain' is the wordplay.
'suit' becomes 'plea' (I've seen this before).
'certain' becomes 'sure' (synonyms).
'plea'+'sure'='PLEASURE'
'to' is the link.
(Other definitions for pleasure that I've seen before include "Delight, joy" , "Delectation, delight" , "A desirable emotion" , "A very desirable feeling" , "entertainment" .)