(Greek mythology) 7 daughters of Atlas and half-sisters of the Pleiades; they nurtured the infant Dionysus and Zeus placed them among the stars as a reward
the number of observations in a given statistical category
the ratio of the number of observations in a statistical category to the total number of observations
the number of occurrences within a given time period; "the frequency of modulation was 40 cycles per second"; "the frequency of his seizures increased as he grew older"