Verona production featuring Romeo went on for too long (7)
I believe the answer is:
overran
'went on for too long' is the definition.
(to overrun is to last too long)
'verona production featuring romeo' is the wordplay.
'production' indicates an anagram.
'featuring' is an insertion indicator.
'romeo' becomes 'R' (phonetic alphabet: alpha, bravo, charlie etc.).
'verona' anagrammed gives 'overan'.
'overan' placed around 'r' is 'OVERRAN'.
(Other definitions for overran that I've seen before include "Stormed" , "Went past an end time" , "Lasted too long" , "Went on too long" , "Went on beyond the time limit" .)