# on guard

> English word · Adjective

## Definitions
1. The starting position of a fencing bout.
2. Vigilant, alert.
3. Transmitting on the aircraft emergency frequency.

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