She had a legendary run entertaining a city in America (8)
I believe the answer is:
atalanta
'she had a legendary run' is the definition.
(in greek mythology)
'entertaining a city in america' is the wordplay.
'entertaining' indicates putting letters inside.
'city in america' becomes 'atlanta'.
'a' placed inside 'atlanta' is 'ATALANTA'.
(Other definitions for atalanta that I've seen before include "fast woman" , "Fabulous runner" , "classically fast runner" , "Fleet-footed Greek maiden" , "Greek runner" .)