flak

/flæk/noun

flak is a noun meaning “Ground-based anti-aircraft guns firing explosive shells” (English Wiktionary, September 2026). It is spelled F-L-A-K and has one syllable, and it appears 1.1 times per million words in written English (wordfreq, 2021 data). The plural of flak is flaks.

What does flak mean?

noun

1
Ground-based anti-aircraft guns firing explosive shells.
2
Anti-aircraft shell fire.
3
informalAdverse criticism.
4
informalA public-relations spokesperson.

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).

How do you pronounce flak?

/flæk/

Flak has one syllable (counted from its American pronunciation in the CMU Pronouncing Dictionary).

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Vealhurl-flak.wav, Wikimedia Commons (author and licence on each file's page).

Forms of flak

flaks plural
flack

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).

How common is flak?

Flak appears 1.1 times per million words in written English, the 26,776th most frequent word form in the list.

flak0.0010.010.11101001,00010,000

rarerper million words of written Englishmore common

Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).

Words people confuse with flak

Word pairs people search, with the monthly searches for “a vs b” (G: Google, B: Bing, United States).

flack vs flak90 G

Sounds like: flack (Wiktionary's homophone list; some hold only in some accents).

Also written: flack.

Sources: Google and Bing searches (September 2025 to August 2026, through DataForSEO); English Wiktionary (homophones, alternative spellings).

Flak in Spanish, French, German and Portuguese

Language	Words
French	lutte anti-aérienne, DCA, défense anti-aérienne (ground-based anti-aircraft guns firing…)
German	Fliegerabwehrkanone, Flugabwehrkanone (ground-based anti-aircraft guns firing…)
Portuguese	bateria antiaérea (ground-based anti-aircraft guns firing…), crítica (adverse criticism)
Spanish	fuego antiaéreo (ground-based anti-aircraft guns firing…), criticismo adverso (adverse criticism)

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.

Where does flak come from?

Borrowed from German FlaK, short for Fliegerabwehrkanone (“anti airplane cannon”).

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).