Expressive Cyril played a lot initially (7)
I believe the answer is:
lyrical
'expressive' is the definition.
(I've seen this before)
'cyril played a lot initially' is the wordplay.
'played' is an anagram indicator.
'initially' indicates taking the first letters.
The first letter of 'lot' is 'l'.
'cyril' is an anagram of 'lyric'.
'lyric'+'a'+'l'='LYRICAL'
(Other definitions for lyrical that I've seen before include "Highly enthusiastic" , "To wax - is to enthuse" , "carried away" , "Using poetic or song-like language" , "Using poetic language, wax thus (7)" .)