Turn pale with certain enjoyment (8)
I believe the answer is:
pleasure
'enjoyment' is the definition.
(thesaurus)
'turn pale with certain' is the wordplay.
'turn' is an anagram indicator.
'with' is a charade indicator (letters next to each other).
'certain' becomes 'sure' ('sure' can be a synonym of 'certain').
'pale' anagrammed gives 'plea'.
'plea'+'sure'='PLEASURE'
(Other definitions for pleasure that I've seen before include "'Enjoyment, delight (8)'" , "entertainment" , "A repulse (anag.)" , "Delectation, delight" , "Delight, happiness" .)