# recursion

Source: https://englishreference.com/word/recursion
Updated: 2026-08-27

## Senses

### 1. self-reference in logic or math

noun · CEFR C1 · Technical · Academic

the act of defining something by using the thing itself.

For teachers: the process of defining an object, function, or concept in terms of itself, typically requiring a base case to prevent infinite loops.

- The teacher used the Fibonacci sequence to explain the concept of recursion.
- In formal logic, recursion allows for the construction of an infinite set of sentences from a finite set of rules and symbols.

Usage: Often used as an uncountable noun when discussing the abstract concept.

### 2. programming procedure

noun · CEFR C1 · Technical

when a computer program calls or runs itself to solve a smaller part of a problem.

For teachers: the invocation of a procedure or subroutine from within its own code block.

- If you don't write a stop condition, the recursion will crash the program.
- The algorithm uses recursion to traverse the complex tree structure, breaking the task into smaller, identical sub-problems.

Usage: Commonly used in the context of 'infinite recursion' to describe a bug where a process never ends.

### 3. the act of recurring

noun · CEFR C2 · Formal

the act of something happening again or repeating.

For teachers: the act of recurring or returning; a repetition of an event or pattern.

- The recursion of these themes in his novels shows his obsession with the past.
- The constant recursion of seasonal patterns provided a sense of stability to the ancient agricultural society.

Teaching tip: In general English, 'recurrence' is much more common for events; 'recursion' is almost always reserved for technical or structural repetition.

## Examples

- The programmer used recursion to sort the list of names.
- Many mathematical formulas use recursion to calculate a result based on the value of the previous step.
- While recursion can lead to elegant and concise code for traversing tree structures, it requires careful management of memory to avoid a stack overflow during deep nesting.

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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.