Tremor of excitement (6)
I believe the answer is:
thrill
'tremor of excitement' is the definition.
(thesaurus)
This is the entire clue.
(Other definitions for thrill that I've seen before include "Excited feeling" , "Titillate" , "Excite, animate" , "D. W. _, pioneer US film director; rigs fifth (anag.)" , "Buzz" .)