time series

American  

noun

1. a set of observations, results, or other data obtained over a period of time, usually at regular intervals.

   Monthly sales figures, quarterly inventory data, and daily bank balances are all time series.

---

time series British  

noun

1. statistics a series of values of a variable taken in successive periods of time

---

Etymology

Origin of time series

First recorded in 1890–95

Example Sentences

This was a drop of 1.8 and 2.5 years compared with the 2019 to 2021 period, and the lowest level since the time series began in 2011 to 2013.

From BBC • Feb. 19, 2026

“It is the longest-running time series that we have on politics, and it allows us to compare presidential performance across presidents and political eras.”

From Salon • Feb. 14, 2026

While the authors did use a type of statistical modeling called an interrupted time series, which in theory allows us to make causal claims here, in practice it’s a bit more complicated.

From Slate • Dec. 3, 2025

The drama made its debut on London Weekend Television in 1971 and became a major prime time series hit for PBS in 1974 when it was imported for U.S. audiences.

From Los Angeles Times • Apr. 13, 2025

Price revisions made in earlier years, changes in the composition of individual statistical categories and other methodological modifications also contributed to the inconsistency of statistical time series in value terms.

From Area Handbook for Bulgaria by Baluyut, Violeta D.