# series

/ˈsɪɹiz/ (US) · /sˈiəɹiz/ (UK)

Source: https://englishreference.com/word/series
Updated: 2026-06-19

## Senses

### 1. a sequence of events

noun · CEFR A2

a number of similar things or events that happen one after another.

For teachers: a number of things, events, or people of a similar kind or nature coming one after another.

- The police are investigating a series of robberies that happened in the city center last week.
- The sudden collapse of the bank triggered a series of financial crises across the continent, forcing governments to intervene with emergency loans.

### 2. TV or radio program

noun · CEFR A2

a set of television or radio programs that have the same characters or theme.

For teachers: a set of related television or radio programmes broadcast in regular installments.

- My favorite comedy series is returning for a third year this autumn.
- The documentary series explores the complex relationship between urban development and local wildlife preservation over the last fifty years.

Usage: The singular form is 'a series' and the plural form is 'two series'.

Teaching tip: In British English, 'series' often means what Americans call a 'season'.

### 3. sports matches

noun · CEFR B1

a group of games played between the same two teams.

For teachers: a set of matches played between two teams or players, often to determine an overall winner.

- The two national teams will play a five-match series starting next month.
- After losing the first two games, the team managed to win the series by securing victories in the final three matches.

### 4. mathematical sum

noun · CEFR C1 · Academic · Technical

the sum of a group of numbers that follow a specific pattern.

For teachers: the sum of the terms of an infinite or finite sequence.

- The teacher asked us to calculate the sum of the geometric series.
- The student struggled to determine whether the infinite series converged to a specific value or diverged toward infinity.

### 5. biological classification

noun · CEFR C2 · Academic · Technical

a way to group living things that are very similar, below a 'genus' but above a 'species'.

For teachers: a taxonomic rank below section but above species, used to group closely related organisms.

- The botanist identified the new plant as belonging to a specific series within the oak family.
- The revision of the genus led to several species being reassigned to a different series based on recent genetic data.

## Examples

- I am watching a new series on television.
- The local library is hosting a series of lectures about history every Tuesday this month.
- The author intended the trilogy to be a continuous narrative, but the publisher insisted on marketing it as a series of standalone novels to attract casual readers.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.