# one-way

> English word · Adjective · IPA /wʌn.weɪ/

## Definitions
1. Allowing movement, vision, etc. in only one direction; unidirectional.
2. Allowing travel in only one direction.
3. Of a function: easy to compute for every input, but hard to invert given the image of a random input.

## Etymology
From one + way. First attested in 1906 in reference to one-way tickets; 1914 in reference to one-way streets; 1940 in reference to one-way mirrors.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-09-03.
Canonical page: https://plainspell.com/en/word/one-way