Host in attendance, extremely eager (9)
I believe the answer is:
presenter
'host' is the definition.
(thesaurus)
'in attendance extremely eager' is the wordplay.
'in attendance' becomes 'present' ('present' can be similar in meaning to 'in attendance').
'extremely' says to hollow out the word (remove centre letters).
'eager' with its middle removed is 'er'.
'present'+'er'='PRESENTER'
(Other definitions for presenter that I've seen before include "Radio/TV personality" , "Disc jockey" , "shower" , "Broadcast introducer" , "TV person" .)