It's sensationally exciting (6)
I believe the answer is:
thrill
If this is the answer I cannot explain how the clue works.
Can you help me to learn more?
(Other definitions for thrill that I've seen before include "Shudder of excitement" , "Exhilarate, excite" , "Intense feeling of delight or excitement" , "gas" , "Almost pleasant sensation of fright" .)