Long-lasting and extremely lucrative account (9)
I believe the answer is:
chronicle
'account' is the definition.
(synonyms)
'long-lasting and extremely lucrative' is the wordplay.
'long-lasting' becomes 'chronic' (I've seen this before).
'and' says to put letters next to each other.
'extremely' means to remove the middle letters.
'lucrative' with its centre taken out is 'le'.
'chronic'+'le'='CHRONICLE'
(Other definitions for chronicle that I've seen before include "(Make a) historical record" , "Record of historic events" , "Story" , "journal" , "History" .)