# red flag

> English word · Noun

## Definitions
1. A flag that is red, especially associated with leftist revolutionary ideologies.
2. A flag that is red, especially associated with leftist revolutionary ideologies.
3. A cue, warning, or alert; a sign or signal that something is wrong.
4. Something that will enrage a particular person; a red rag.
5. A flag formerly used by a railway guard to warn the driver not to start the train.

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