Excited at talk, pointlessly (8)
I believe the answer is:
atwitter
'excited' is the definition.
(atwitter can mean in a state of excitement)
'at talk pointlessly' is the wordplay.
'talk pointlessly' becomes 'witter' (to witter is to talk about pointless matters).
'at'+'witter'='ATWITTER'
(Other definitions for atwitter that I've seen before include "excited" , "very chirpy?" , "Noisy" .)