Effusive (9)
(Other definitions for exuberant that I've seen before include "Abounding in vitality" , "Elated" , "High-spirited" , "Full of energy, high spirits" , "full of glee" .)
'effusive' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for lyrical that I've seen before include "Using poetic language, wax thus (7)" , "Effusive" , "To wax - is to enthuse" , "Highly enthusiastic" , "Using poetic or song-like language" .)