frequency

(noun) the number of occurrences within a given time period. Synonyms: frequence, oftenness. Examples: "The frequency of modulation was 40 cycles per second." "The frequency of his seizures increased as he grew older."

(noun) the ratio of the number of observations in a statistical category to the total number of observations. Synonyms: relative frequency.

(noun) the number of observations in a given statistical category. Synonyms: absolute frequency.