One star (3)
I believe the answer is:
ace
I believe this is a double definition.
'one' is the first definition.
('ace' can be a synonym of 'one')
'star' is the second definition.
('ace' can be a synonym of 'star')
(Other definitions for ace that I've seen before include "winner in court" , "Top card or champion" , "Winning serve; hole in one" , "Service that's never returned" , "Unreturnable serve" .)