Mode
The mode of a set of numbers is the number that occurs most frequently. There may be more than one mode. In the set (1,4,5,7), all four numbers are modes. But in the set (1,4,4,6), 4 is the only mode. The mode is one of the measures of central tendency, the others being the mean and the median.
Additional topics
Science EncyclopediaScience & Philosophy: Methane to Molecular clock