verb (1)
\ ˈfȯi(-ə)l How to pronounce foil (audio) \
foiled; foiling; foils

Definition of foil

 (Entry 1 of 5)

transitive verb

1a : to prevent from attaining an end : defeat always able to foil her enemies Her accident foiled her from becoming a dancer.
b : to bring to naught : thwart foiled the plot Police foiled an attempted robbery.
2 obsolete : trample


noun (1)

Definition of foil (Entry 2 of 5)

1 : very thin sheet metal aluminum foil
2 : a thin piece of material (such as metal) put under an inferior or paste stone to add color or brilliance
3 : someone or something that serves as a contrast to another acted as a foil for a comedian
4a : an indentation between cusps in Gothic tracery
b : one of several arcs that enclose a complex figure


verb (2)
foiled; foiling; foils

Definition of foil (Entry 3 of 5)

transitive verb

1 : to back or cover with foil
2 : to enhance by contrast


noun (2)

Definition of foil (Entry 4 of 5)

1 : a light fencing sword having a usually circular guard and a flexible blade of rectangular section tapering to a blunted point — compare épée, saber
2 : the art or sport of fencing with the foil often used in plural


noun (3)

Definition of foil (Entry 5 of 5)

1 archaic : defeat
2 archaic : the track or trail of an animal

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Synonyms & Antonyms for foil

Synonyms: Verb (1)

Antonyms: Verb (1)

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Choose the Right Synonym for foil

Verb (1)

frustrate, thwart, foil, baffle, balk mean to check or defeat another's plan or block achievement of a goal. frustrate implies making vain or ineffectual all efforts however vigorous or persistent. frustrated attempts at government reform thwart suggests frustration or checking by crossing or opposing. the army thwarted his attempt at a coup foil implies checking or defeating so as to discourage further effort. foiled by her parents, he stopped trying to see her baffle implies frustration by confusing or puzzling. baffled by the maze of rules and regulations balk suggests the interposing of obstacles or hindrances. officials felt that legal restrictions had balked their efforts to control crime

First Known Use of foil

Verb (1)

14th century, in the meaning defined at sense 2

Noun (1)

14th century, in the meaning defined at sense 1

Verb (2)

1611, in the meaning defined at sense 1

Noun (2)

1594, in the meaning defined at sense 1

Noun (3)

15th century, in the meaning defined at sense 1

History and Etymology for foil

Verb (1) and Noun (3)

Middle English, alteration of fullen to full cloth, from Anglo-French foller — more at full

Noun (1)

Middle English, leaf, from Anglo-French fuille, foille (from Latin folia, plural of folium) & fuil, from Latin folium — more at blade

Noun (2)

origin unknown

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Learn More About foil

Time Traveler for foil

Time Traveler

The first known use of foil was in the 14th century

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Dictionary Entries Near foil

foie gras



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Cite this Entry

“Foil.” Dictionary, Merriam-Webster, Accessed 16 Sep. 2021.

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More Definitions for foil


\ ˈfȯil How to pronounce foil (audio) \
foiled; foiling

Kids Definition of foil

 (Entry 1 of 3)

: to prevent from achieving a goal Police foiled the bank robbery.



Kids Definition of foil (Entry 2 of 3)

: a very thin sheet of metal aluminum foil



Kids Definition of foil (Entry 3 of 3)

: a fencing sword having a light flexible blade with a blunt point


\ ˈfȯil How to pronounce foil (audio) \

Medical Definition of foil

: very thin sheet metal (as of gold or platinum) used especially in filling teeth

More from Merriam-Webster on foil

Nglish: Translation of foil for Spanish Speakers

Britannica English: Translation of foil for Arabic Speakers Encyclopedia article about foil


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