ˌlowest ˌcommon deˈnominator BrE AmE noun [uncountable]
1 . the biggest possible number of people, including people who are very easily influenced or are willing to accept low standards:
Television quiz shows often seem to target the lowest common denominator.
2 . technical the smallest number that the bottom numbers of a group of ↑ fraction s can be divided into exactly ⇨ ↑ denominator