Common denominator refers to the shared trait or characteristic of a group. Synonyms for common denominator include shared trait, common factor, common thread, unifying element, and common ground. A shared trait is something that multiple individuals or objects have in common, such as a similar upbringing or interest. A common factor is a number that can divide into each member of a group. A common thread is a consistent theme or idea that runs throughout a larger concept. An unifying element is a factor that brings individuals or groups together despite their differences. Common ground refers to the agreement or overlap between ideas, beliefs, or values.