# foil

/ˈfɔɪɫ/ (US) · /fˈɔɪl/ (UK)

Source: https://englishreference.com/word/foil
Updated: 2026-06-20

## Senses

### 1. metal sheet

noun · CEFR B1

a very thin, flexible sheet of metal, usually aluminium, used to wrap food.

For teachers: a very thin sheet of metal, typically aluminium, used for culinary or industrial wrapping.

- She covered the leftover chicken with aluminium foil before putting it in the fridge.
- The chef insisted on wrapping the beetroot in heavy-duty foil to ensure it roasted evenly in its own juices.

### 2. a person who contrasts

noun · CEFR C1 · Academic · Literary

a person or thing that makes another's qualities more obvious by being very different.

For teachers: a person or thing that contrasts with and so emphasizes the qualities of another, often used in literary analysis.

- In the story, the serious detective is a perfect foil for his funny partner.
- The protagonist's impulsive nature is highlighted by the presence of a cautious, analytical foil who questions every decision.

### 3. fencing sword

noun · CEFR B2

a light, thin sword with a blunt tip used in the sport of fencing.

For teachers: a light fencing sword with a flexible quadrangular blade and a blunt point.

- He practiced his footwork for an hour before picking up his foil for the match.
- The fencer scored a decisive point by using her foil to parry the opponent's lunge and counter-attack quickly.

### 4. wing or fin

noun · CEFR C1 · Technical

a short name for a wing-like part that helps a boat or plane lift up.

For teachers: a shortened form of hydrofoil or aerofoil, referring to a structure that creates lift in water or air.

- The high-speed ferry rose up on its foils as it gained speed in the harbour.
- Engineers adjusted the angle of the foils to reduce drag and improve the vessel's fuel efficiency at cruising speeds.

### 5. to stop a plan

verb · CEFR B2

to stop someone from doing something they planned, especially something bad.

For teachers: to prevent a person from succeeding in a plan or to thwart an effort.

- The police managed to foil the robbery after a witness called them.
- The security team successfully foiled the attempted data breach by isolating the compromised server within minutes.

## Examples

- The serious detective needs a funny partner to act as a foil.
- In the novel, the protagonist's cautious nature is highlighted by his adventurous friend, who serves as a perfect foil.
- The architect used rough, unpolished stone as a foil to the sleek glass panels, creating a visual tension that defined the building's facade.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.