Type of sensation having appeal? Certainly (8)
I believe the answer is:
pleasure
'type of sensation' is the definition.
The answer and definition can be both related to thinking as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'appeal? certainly' is the wordplay.
'appeal?' becomes 'plea' (plea is a kind of appeal).
'certainly' becomes 'sure' (synonyms).
'plea'+'sure'='PLEASURE'
'having' acts as a link.
Can you help me to learn more?
(Other definitions for pleasure that I've seen before include "A very desirable feeling" , "entertainment" , "Gratification of the senses" , "Happy satisfaction" , "contentment" .)