red flag

noun

By · According to Wiktionary data (CC BY-SA) ·

"red-flag" is a 7-letter English headword indexed on PlainSpell.

The verdict

“red flag” is uncommon English (outside the top frequency list), classed as a noun. The kind of spelling people second-guess.

Unranked
below top-frequency English
8
letters

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - A flag that is red, especially associated with leftist revolutionary ideologies.

Key facts for red flag
PropertyValue
Headwordred flag
LanguageEnglish
Part of speechNoun
Letters8
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Where “red flag” sits in English frequency

red flag falls outside the top-100,000 ranked English words, the long-tail zone of technical, archaic, or low-frequency vocabulary, exactly where readers second-guess spellings most.

Beyond rank #100,000. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

red flag is uncommon English outside the top frequency list, classed as anoun. Rarity is why readers land here mid-draft. 5 senses are on record.

No generated misspelling entries exist for red flag in our index, since its letter sequence doesn't invite the usual edit-distance slips. This headword has no recorded confusable partner, suggesting its spelling stands apart enough that readers rarely confuse it with something else.

This entry's etymology isn't recorded, so its spelling is best explained by sound-to-letter mapping rather than etymology. The correct English form is red flag, spelled R-E-D- -F-L-A-G.

Definition

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

This word in other languages

alerta(Español)avertissement(Français)Warnsignal(Deutsch)

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "red flag"?
"red flag" is spelled R-E-D- -F-L-A-G.
What does "red flag" mean?
As a noun, "red flag" means: A flag that is red, especially associated with leftist revolutionary ideologies.
What language does "red flag" come from?
"red flag" is a English word. PlainSpell's reference spans five languages -- English, Spanish, Portuguese, French, and German -- with definitions, pronunciations, and spelling data for each.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Using “red flag”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is R-E-D- -F-L-A-G - every other letter order is a misspelling in standard orthography.
  • Browse more English words and confusable pairs in the same reference. English words
Data Source

Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list