An official count or enumeration of members of a population (not necessarily human), usually residents or citizens in a particular region, often done at regular intervals.
Count, tally.
To collect a census.
To conduct a census on.
A systematic collection of data on measurements or observations, often related to demographic information such as population counts, incomes, population counts at different ages, etc.
A discipline, principally within applied mathematics, concerned with the systematic study of the collection, presentation, analysis, and interpretation of data.