All excited (5,2)
'all excited' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for agog that I've seen before include "Very curious to hear" , "Interested, excited and eager to know more" , "Excitedly interested" , "Open-mouthed" , "On tenterhooks" .)
(Other definitions for keyed up that I've seen before include "Tense and nervous" , "On tenterhooks" , "Tense and excited" .)