1. a branch of applied mathematics concerned with the collection and interpretation of quantitative data and the use of probability theory to estimate population parameters;

The Collaborative International Dictionary of English v.0.48:

Statistics \Sta*tis"tics\ (st[.a]*t[i^]s"t[i^]ks), n. [Cf. F. statistique, G. statistik. See State, n.] 1. The science which has to do with the collection, classification, and analysis of facts of a numerical nature regarding any topic. Specifically: The science dealing with collection, tabulation, and analysis of facts respecting the condition of the people in a state. Note: [In this sense grammatically singular.] [1913 Webster] 2. pl. Classified facts of a numerical nature regarding any topic. Specifically: (a) Numerical facts respecting the condition of the people in a state, their health, their longevity, domestic economy, arts, property, and political strength, their resources, the state of the country, etc., or respecting any particular class or interest; especially, those facts which can be stated in numbers, or in tables of numbers, or in any tabular and classified arrangement. (b) (Sport) Numerical facts regarding the performance of athletes or athletic teams, such as winning percentages, numbers of games won or lost in a season, batting averages (for baseball players), total yards gained (for football players). The creation and classification of such numbers is limited only by the imagination of those wishing to describe athletic performance numerically. Syn: stats. [1913 Webster +PJC] 3. The branch of mathematics which studies methods for the calculation of probabilities. [PJC]WordNet (r) 3.0 (2006):

statistics n 1: a branch of applied mathematics concerned with the collection and interpretation of quantitative data and the use of probability theory to estimate population parametersThe Free On-line Dictionary of Computing (30 December 2018):

statisticsThe practice, study or result of the application of mathematical functions to collections of data in order to summarise or extrapolate that data. The subject of statistics can be divided into descriptive statistics - describing data, and analytical statistics - drawing conclusions from data. (1997-07-16)