Confidently optimistic and cheerful (8)
I believe the answer is:
sanguine
'confidently optimistic and cheerful' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for sanguine that I've seen before include "Hopeful of winning - or ruddy" , "Optimistic or ruddy" , "Hopeful or optimistic" , "Confidently optimistic and cheerful" , "Confident < , or > ruddy" .)