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PlainSpell

foil

/fɔɪl/noun, verb

foil is spelled F-O-I-L: 4 letters and one syllable. It appears 5.8 times per million words in written English, the 10,196th most frequent word form (wordfreq, 2021 data). As a noun, foil means “A very thin sheet of metal” (English Wiktionary, September 2026). The plural of foil is foils.

How many letters and syllables are in foil?

Letters4: F-O-I-L
Syllables1 (from its American pronunciation)
In writing5.8 times per million words; the 10,196th most frequent word form
Wrong spellings searchednone measured in search

Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation and the CMU Pronouncing Dictionary; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).

How common is foil?

Foil appears 5.8 times per million words in written English, the 10,196th most frequent word form in the list.

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

How do you pronounce foil?

  • /fɔɪl/

Foil 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)-Flame,_not_lame-FOIL.wav, En-us-foil.ogg, Wikimedia Commons (author and licence on each file's page).

Forms of foil

  • foils plural, present, singular, he/she/it
  • foiling participle, present
  • foiled participle, past

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

What does foil mean?

The meanings the English Wiktionary records, quoted as written there (source below).

noun

  1. 1

    A very thin sheet of metal.

  2. 2

    A very thin sheet of plastic.

  3. 3

    Thin aluminium/aluminum (or, formerly, tin) used for wrapping food.

    wrap the sandwich up in foil

  4. 4

    A thin layer of metal put between a jewel and its setting to make it seem more brilliant.

  5. 5

    In literature, theatre/theater, etc., a character who helps emphasize the traits of the main character and who usually acts as an opponent or antagonist, but can also serve as the sidekick of the protagonist.

  6. 6

    Anything that acts by contrast to emphasise the characteristics of something.

  7. 7

    A very thin sword with a blunted (or foiled) tip.

  8. 8

    A thin, transparent plastic material on which marks are made and projected for the purposes of presentation. See transparency.

  9. 9

    Failure when on the point of attainment; defeat; frustration; miscarriage.

  10. 10

    One of the incorrect answers presented in a multiple-choice test.

  11. 11

    The track of an animal.

  12. 12

    A small arc in the tracery of a window, etc.

verb

  1. 1

    To cover or wrap with foil.

  2. 2

    Clipping of hydrofoil.

  3. 3

    To prevent (something) from being accomplished.

    They foiled my plans.

  4. 4

    To prevent (someone) from accomplishing something.

    I was foiled by my superior

  5. 5

    To blunt; to dull; to spoil.

  6. 6

    obsoleteTo tread underfoot; to trample.

  7. 7

    To expand a product of two or more algebraic expressions, typically binomials.

  8. 8

    obsoleteTo defile; to soil.

verb

as FOIL
  1. 1

    To apply the FOIL algorithm to.

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

Foil in Spanish, French, German and Portuguese

LanguageWords
Frenchfeuille de métal (thin sheet of metal), papier d'aluminium, alu (thin aluminium/aluminum or tin used for…), fleuret (type of sword used in fencing), faire-valoir (character who helps emphasise the traits of the…), déjouer (prevent from being accomplished)
GermanFolie (thin sheet of metal), Aluminiumfolie (thin aluminium/aluminum or tin used for…), Florett (type of sword used in fencing), Kontrastfigur (character who helps emphasise the traits of the…), hintertreiben (prevent from being accomplished)
Portuguesefolha (thin sheet of metal), papel-alumínio (thin aluminium/aluminum or tin used for…), florete (type of sword used in fencing), frustrar (prevent from being accomplished)
Spanishlámina de metal, folio (thin sheet of metal), papel de aluminio (thin aluminium/aluminum or tin used for…), florete (type of sword used in fencing), frustrar (prevent from being accomplished), complemento (anything that acts to emphasise the…)

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 foil come from?

From Middle English foyle, from Middle French fueille, from Old French fueille (“plant leaf”), from Late Latin folia, the plural of folium, mistaken as a singular feminine. The literary sense is from the practice of backing a gem with metal foil to make it shine more brilliantly. Doublet of folio and folium, distantly also with phyllo and phyllon.

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

What to look up after foil