flask

/ˈflɑːsk/

//ˈflɑːsk// noun

"flask" is a 5-letter English headword indexed on PlainSpell.

The verdict

“flask” is a moderately-common English word, ranked #22,379 in English word frequency and used as a noun.

#22,379
frequency rank, English
5
letters
8
tracked misspellings
20
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - A narrow-necked vessel of metal or glass, used for various purposes; as of sheet metal, to carry gunpowder in; or of wrought iron, to contain quicksilver; or of glass, to heat water in, etc.

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

flask vs flat
60% similar
flask vs flaw
60% similar
flask vs flax
60% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for flask
PropertyValue
Headwordflask
LanguageEnglish
Part of speechNoun
IPA/ˈflɑːsk/
Letters5
Frequency rank#22,379
Misspellings tracked8
Confusable pairs20
SourceWiktionary (kaikki.org)

Where “flask” sits in English frequency

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right). flask lands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

Spelling & Dictionary Insight

The English entry for flask is 5 letters long, classified as a noun, and transcribed in the International Phonetic Alphabet as /ˈflɑːsk/. Corpus data places it at rank #22,379 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. Wiktionary records 7 distinct senses for this headword, so context determines which meaning a reader should apply.

Our generated misspelling index lists 8 likely wrong-spelling variants for flask, with forms such as "falsk", "fflask", and "flaks". Each variant is a distinct typo pattern an edit-distance generator flags, typically a doubled-consonant error, a silent-letter drop, or a vowel substitution. It also participates in 20 confusable-pair relationships, "flat", "flaw", "flax", and more, a pairing that trips writers up because the two words share enough sound or shape to blur together.

Etymologically, the entry records: From Middle English flask, flaske (“case, cask, keg”), from Old English flasce, flaxe (“bottle, flask”) and Medieval Latin flascō (“bottle”); from Frankish *flaskā; both from Proto-Germanic *flaskǭ (“braid-covered bottle, wicker-enclosed jug”), from Proto-I… The correct English form is flask, spelled F-L-A-S-K.

Definition

  1. 1
    A narrow-necked vessel of metal or glass, used for various purposes; as of sheet metal, to carry gunpowder in; or of wrought iron, to contain quicksilver; or of glass, to heat water in, etc.
  2. 2
    A container used to discreetly carry a small amount of a hard alcoholic beverage; a pocket flask.
  3. 3
    Laboratory glassware used to hold larger volumes than test tubes, normally having a narrow mouth of a standard size which widens to a flat or spherical base.
  4. 4
    A container for holding a casting mold, especially for sand casting molds.
  5. 5
    A bed in a gun carriage.
  6. 6
    A nuclear flask, a large, secure lead-lined container for the transport of nuclear material.
  7. 7
    A small bottle of liquor.

Etymology

From Middle English flask, flaske (“case, cask, keg”), from Old English flasce, flaxe (“bottle, flask”) and Medieval Latin flascō (“bottle”); from Frankish *flaskā; both from Proto-Germanic *flaskǭ (“braid-covered bottle, wicker-enclosed jug”), from Proto-Indo-European *ploḱ-skō (“flat”), or from Proto-Indo-European *pleḱ- (“to weave”). Doublet of fiasco, flacon, and flagon. Related to Dutch fles; also German Low German Flaske, Fless, German Flasche, Danish flaske; also Lithuanian plókščias, Czech ploský, Albanian flashkët. The sense “laboratory glassware” is from Italian fiasco, and the sense “container for holding a casting mold” is from Middle French flasque (“powder flask”), itself from Old Spanish flasco, frasco, both from Late Latin above.

This word in other languages

Common misspellings

Also misspelled as: falsk,fflask,flaks,flaskk,flassk,fllask,flsak,lfask

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of flask - counted as single-character edits (an insertion, a deletion, or a substituted letter). The larger the bar, the easier the typo is to spot; one-edit slips are the ones that sneak past readers.

falsk2fflask1flaks2flaskk1flassk1fllask1flsak2lfask2
Edit distance from "flask"

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "flask"?
"flask" is spelled F-L-A-S-K. The IPA pronunciation is /ˈflɑːsk/.
What does "flask" mean?
As a noun, "flask" means: A narrow-necked vessel of metal or glass, used for various purposes; as of sheet metal, to carry gunpowder in; or of wrought iron, to contain quicksilver; or of glass, to heat water in, etc.
What words are commonly confused with "flask"?
"flask" is commonly confused with "flat", "flaw", "flax". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "flask"?
The IPA (International Phonetic Alphabet) transcription for "flask" is /ˈflɑːsk/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "flask"?
From Middle English flask, flaske (“case, cask, keg”), from Old English flasce, flaxe (“bottle, flask”) and Medieval Latin flascō (“bottle”); from Frankish *flaskā; both from Proto-Germanic *flaskǭ (“braid-covered bottle, wicker-enclosed jug”), fr... See the full etymology section above for more details.
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 “flask”

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

  • The one correct English spelling is F-L-A-S-K - every other letter order is a misspelling in standard orthography.
  • Say it as /ˈflɑːsk/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • Don't mix it up with “flat” - see the side-by-side comparison. flask vs flat
  • 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 FrequencyWords open word-frequency list