Strike is a success (3)
I believe the answer is:
hit
I believe this is a double definition.
'strike' is the first definition.
(I know that strike can be written as hit)
'success' is the second definition.
(a hit is a commercial success)
'is a' acts as a link.
(Other definitions for hit that I've seen before include "Knock" , "Theatrical success,quite striking" , "Successful record/film" , "that pleases the public" , "Popular record" .)