Rock flower (6)
I believe the answer is:
hudson
I believe this is a double definition.
'rock' is the first definition.
(American actor Rock Hudson)
'flower' is the second definition.
(Hudson River, something which 'flows')
(Other definitions for hudson that I've seen before include "ROCK] a > banker" , "Large bay in Canada" , "Major inland sea of NE Canada - . . . . . . Bay" , "River in New York city" , "Rock -, - bay" .)