What does "foil" mean?
A very thin sheet of metal or plastic.
Foil
/fɔɪl/ name, noun, verb
name, noun, verb ·Very common ·Middle school level
Meaning at a glance
- Primary sense: A very thin sheet of metal or plastic.
- Grammar: foil is listed as name, noun, verb.
- Nearest alternatives: actor, actress, aluminum sheet, antagonise.
- Useful contrasts: aid, assist, blend with.
- Usage evidence: Make balls 3 centimeters in diameter and place them on a sheet of buttered aluminum foil.
How to use "foil"
- Start with the primary definition, then check the part of speech before placing the word in a sentence.
- Compare nearby synonyms to make sure "foil" carries the exact meaning, tone, and strength you need.
- Use the example sentence as a context check. If your sentence uses the word differently, confirm that the grammar still fits.
Meaning check
- Does the word fit the sentence's grammar?
- Does it match the intended tone rather than only the dictionary definition?
- Would a simpler synonym be clearer for the reader?
- Is there enough surrounding context to prevent ambiguity?
Source and review context
This entry combines structured lexical data with WordToolSet review checks. Definitions, examples, synonyms, and usage notes may come from different source tables, so the page is designed to show evidence from more than one angle before you rely on "foil" in a final draft.
If a word has several senses, prefer the sense that matches your sentence's grammar and surrounding context. A correct definition can still be the wrong choice when the sentence needs a different register, emphasis, or level of specificity.
Before you rely on this definition
Read the first definition as a starting point, then check the example, synonyms, and part of speech before treating "foil" as the right word for your sentence.
If your draft is formal, technical, persuasive, or sensitive, compare "foil" with a nearby alternative so the final choice matches both meaning and reader expectation.
Compare nearby meanings
- Use synonyms when you need a softer, stronger, simpler, or more specific word.
- Use antonyms to check the boundary of the meaning and avoid accidental contrast.
- Use the example sentence to confirm the word behaves naturally in context.
- Keep the original wording when a replacement adds complexity without improving precision.
Definition decision workflow
1. Identify the role
Check whether "foil" is acting as name, noun, verb in your sentence. A definition is only useful when the grammar matches the way the word is being used.
2. Test the nearest option
Compare it with "actor" and other nearby choices to see whether the sentence needs a softer, stronger, or more familiar word.
3. Confirm with context
Use the example sentence below as an evidence check, then read your own sentence out loud to catch tone or rhythm problems.
Review note: Definition pages are checked for source coverage, sentence evidence, synonym support, and editorial insight before they are treated as approval-ready pages. If the evidence is too thin, the page remains available to users but is kept out of the approval-facing indexed inventory.
Final meaning check
Before publishing a sentence with "foil", ask whether the word helps the reader understand the idea faster. A precise word should reduce confusion, not simply make the sentence look more polished.
When the definition, synonym evidence, and example context point in the same direction, the word is usually a safer choice. When they conflict, revise the sentence or choose a clearer alternative.
Definitions
Noun
- 1 A very thin sheet of metal or plastic. countable, uncountable
- 2 Failure when on the point of attainment; defeat; frustration; miscarriage.
"Fame is no plant that grows on mortal foil"
- 3 The track of an animal.
"[…]but after giving her a dodge, here's another b— follows me upon the foil."
- 4 A small arc in the tracery of a window, etc.
- 5 a light slender flexible sword tipped by a button wordnet
Show 15 more definitions
- 6 Thin aluminium/aluminum (or, formerly, tin) used for wrapping food. uncountable
"wrap the sandwich up in foil"
- 7 One of the incorrect answers presented in a multiple-choice test.
- 8 a piece of thin and flexible sheet metal wordnet
- 9 A thin layer of metal put between a jewel and its setting to make it seem more brilliant. countable, uncountable
- 10 picture consisting of a positive photograph or drawing on a transparent base; viewed with a projector wordnet
- 11 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. countable, figuratively, uncountable
"Whereas the female invests heavily in the wake of conception, the male invests heavily prior to conception. Hitherto, the male has been regarded as the mere foil to the heavy investment in reproduction that renders the female the logjam (the limiting factor) in reproduction – reproduction overall is expandable by increasing the number of females, not by increasing the number of males."
- 12 a device consisting of a flat or curved piece (as a metal plate) so that its surface reacts to the water it is passing through wordnet
- 13 Anything that acts by contrast to emphasise the characteristics of something. countable, figuratively, uncountable
"As she a black silk cap on him begun / To set, for foil of his milk-white to serve."
- 14 anything that serves by contrast to call attention to another thing's good qualities wordnet
- 15 A very thin sword with a blunted (or foiled) tip countable, uncountable
"Blunt as the fencer's foils, which hit, but hurt not."
- 16 A thin, transparent plastic material on which marks are made and projected for the purposes of presentation. See transparency. countable, uncountable
- 17 A premium trading card with a glossy finish. countable, uncountable
"I personally would collect all the foils from Base Set before this one, but the market is what the market is."
- 18 A stylized flower or leaf. countable, uncountable
- 19 Clipping of hydrofoil. abbreviation, alt-of, clipping, countable, uncountable
- 20 Clipping of aerofoil/airfoil. abbreviation, alt-of, clipping, countable, uncountable
Verb
- 1 To apply the FOIL algorithm to. transitive
- 2 To cover or wrap with foil. transitive
- 3 To prevent (something) from being accomplished.
"They foiled my plans."
- 4 To expand a product of two or more algebraic expressions, typically binomials.
- 5 To defile; to soil. obsolete
Show 7 more definitions
- 6 cover or back with foil wordnet
- 7 Clipping of hydrofoil. abbreviation, alt-of, clipping
- 8 To prevent (someone) from accomplishing something.
"I was foiled by my superior"
- 9 hinder or prevent (the efforts, plans, or desires) of wordnet
- 10 To blunt; to dull; to spoil.
"they foil the scent of one another."
- 11 enhance by contrast wordnet
- 12 To tread underfoot; to trample. obsolete
"King Richard […] caused the ensigns of Leopold to be pulled down and foiled underfoot."
Proper Noun
- 1 An acronym for the algorithm for multiplying two binomials. mnemonic
Synonyms
All synonymsExample
"Make balls 3 centimeters in diameter and place them on a sheet of buttered aluminum foil."
Common questions
What is a synonym for "foil"?
Common synonyms include: actor, actress, aluminum sheet, antagonise, antagonist, antagonized.
How do you use "foil" in a sentence?
Make balls 3 centimeters in diameter and place them on a sheet of buttered aluminum foil.
How do you pronounce "foil"?
Pronounced /fɔɪl/.
Etymology
Etymology 1
Acronym of first outer inner last or similar.
Etymology 2
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.
Etymology 3
From Middle English foilen (“spoil a scent trail by crossing it”), from Old French fouler (“tread on, trample”), ultimately from Latin fullō (“I trample, I full”).
Etymology 4
From French foulis.
Etymology 5
From mnemonic acronym FOIL (“First Outside Inside Last”).
Etymology 6
See file.