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.

FOIL definition: 1. a very thin sheet of metal, especially used to wrap food in to keep it fresh: 2. a piece of a…. Learn more.

foils, the art or practice of fencing with this weapon, points being made by touching the trunk of the opponent's body with the tip of the weapon.

One that stands in contrast to and emphasizes the distinctive characteristics of another: "I am resolved my husband shall not be a rival, but a foil to me" (Charlotte Brontë).

Nov 29, 2025 · foil (countable and uncountable, plural foils) A very thin sheet of metal. (chiefly uncountable) Thin aluminium / aluminum (or, formerly, tin) used for wrapping food. A thin layer of …

Definition of foil noun in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

a person or thing that makes another seem better by contrast: The straight man was an able foil to the comic. Architecture an arc or a rounded space between cusps, as in the tracery of a window or other …