From Longman Dictionary of Contemporary Englishstar signˈstar sign (also sign) noun [countable] ROAone of the 12 signs of the zodiac (=the system that uses people’s birth dates to say what will happen to them in the future)
Examples from the Corpus
star sign• My friend Rachel knows his star sign and has taken every compatibility test the Crowe fan sites have thrown at her.• Perhaps it was simply due to his star sign.• You're not still going on about all that star sign nonsense, are you?• A man whose star sign made him her exact opposite.