# first in first out

> English word · Noun

## Definitions
1. A method of inventory accounting that values items withdrawn from inventory at the cost of the oldest item assumed to remain in inventory.
2. A policy of assigning priority to tasks and assignments that have arrived for service first.
3. A type of queue data structure in which the oldest added items are retrieved first.

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