# Fibonacci sequence

> English word · Noun

## Definitions
1. The sequence of integers, each of which is the sum of the preceding two, the first and second numbers both being 1.
2. Any sequence of numbers such that each is the sum of the preceding two.

## Etymology
Named after the Italian mathematician later known as Fibonacci (c.1175 – c.1250), who introduced the sequence to a European readership in his 1202 book Liber Abaci.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/fibonacci-sequence