*SET-U

English word origin

Etymology of foil

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 back

5 source sectionsExtended source reportWiktionary original ↗
In this entry · 5 source sections

The source etymologies

Wiktionary via Kaikki / Wiktextract

The source reports below are imported and unreviewed by *SET-U. Separate numbered origins and differing source variants are preserved; agreement within this extraction is not independent corroboration.

Source etymology 1

Original entry ↗
verb

To cover or wrap with foil. · Clipping of hydrofoil.

noun

A very thin sheet of metal. · A very thin sheet of plastic. · Thin aluminium/aluminum (or, formerly, tin) used for wrapping food. · A thin layer of metal put between a jewel and its setting to make it seem more brilliant.

Selected source glosses provide context, not a complete modern definition inventory

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.

Relationships mentioned by the source

These are extracted mentions, not a timeline or a verified sequence of immediate parents.

This page abbreviates 8 auxiliary source items. The etymology narrative is not shortened. Omission counts are available in the audit fields below; consult the original for complete auxiliary material.

Inspect preserved source fields

Raw extraction fields are retained for auditing. Their order does not establish ancestry.

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Source etymology 2

Original entry ↗
verb

To prevent (something) from being accomplished. · To prevent (someone) from accomplishing something. · To blunt; to dull; to spoil. · To tread underfoot; to trample.

noun

Failure when on the point of attainment; defeat; frustration; miscarriage. · One of the incorrect answers presented in a multiple-choice test.

Selected source glosses provide context, not a complete modern definition inventory

From Middle English foilen (“spoil a scent trail by crossing it”), from Old French fouler (“tread on, trample”), ultimately from Latin fullō (“to trample, full”).

Relationships mentioned by the source

These are extracted mentions, not a timeline or a verified sequence of immediate parents.

Inspect preserved source fields

Raw extraction fields are retained for auditing. Their order does not establish ancestry.

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Source etymology 3

Original entry ↗
noun

The track of an animal.

Selected source glosses provide context, not a complete modern definition inventory

From French foulis.

Relationships mentioned by the source

These are extracted mentions, not a timeline or a verified sequence of immediate parents.

Inspect preserved source fields

Raw extraction fields are retained for auditing. Their order does not establish ancestry.

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Source etymology 4

Original entry ↗
verb

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

Selected source glosses provide context, not a complete modern definition inventory

From mnemonic acronym FOIL (“First Outside Inside Last”).

Inspect preserved source fields

Raw extraction fields are retained for auditing. Their order does not establish ancestry.

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Source etymology 5

Original entry ↗
verb

To defile; to soil.

Selected source glosses provide context, not a complete modern definition inventory

See file.

Inspect preserved source fields

Raw extraction fields are retained for auditing. Their order does not establish ancestry.

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Where this record stops

This page does not supply an independently verified sound-change sequence, first-use manuscript or complete family tree unless a cited analysis explicitly establishes one. Missing detail here is a limit of this record—not a claim that humanity knows nothing more.

An older meaning does not determine what a word must mean today. Follow the sources, preserve disagreements, and keep ancestry separate from interpretation.

Contribute located evidence for foil →

Source and snapshot

Imported from Wiktionary contributors; extracted by Tatu Ylonen / Wiktextract / Kaikki.org. Selected fields are reformatted and grouped; wording, source identity and etymology sections are retained. CC-BY-SA-4.0 applies to the imported source material.

Dump: 2026-10-01 · Extracted: 2026-10-30. These are snapshot dates, not the word’s first attestation or the page’s revision date.

Source entry and bibliography ↗Wiktionary revision history ↗Acquisition and rights ledger
Machine-source provenance
Source SHA-256
5ff2c072f8099f2d2ce484bd6957bf179f046d2ad37bc36555edf8bb84cb5291
Import run
73216b9a9b78ed3830994bf853103716f5a4dc57099e371e9f8fdc468facca26
Permanent entry ID
w-Zm9pbA