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REFERENCE

foil

n. · v.
US //ˈfɔɪɫ// UK //fˈɔɪl// foil
  1. 1 metal sheet (n.)
    B1 Intermediate Cooking

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

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

    Example

    She covered the leftover chicken with aluminium foil before putting it in the fridge.

    Example

    The chef insisted on wrapping the beetroot in heavy-duty foil to ensure it roasted evenly in its own juices.

  2. 2 a person who contrasts (n.)
    C1 Advanced Academic Literary Theatre

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

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

    Example

    In the story, the serious detective is a perfect foil for his funny partner.

    Example

    The protagonist's impulsive nature is highlighted by the presence of a cautious, analytical foil who questions every decision.

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  1. 3 fencing sword (n.)
    B2 Upper Intermediate Sport

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

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

    Example

    He practiced his footwork for an hour before picking up his foil for the match.

    Example

    The fencer scored a decisive point by using her foil to parry the opponent's lunge and counter-attack quickly.

  2. 4 wing or fin (n.)
    C1 Advanced Technical Technical

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

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

    Example

    The high-speed ferry rose up on its foils as it gained speed in the harbour.

    Example

    Engineers adjusted the angle of the foils to reduce drag and improve the vessel's fuel efficiency at cruising speeds.

  3. 5 to stop a plan (v.)
    B2 Upper Intermediate

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

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

    Example

    The police managed to foil the robbery after a witness called them.

    Example

    The security team successfully foiled the attempted data breach by isolating the compromised server within minutes.

Etymology 1

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 2

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”).

Etymology 3

From French foulis.

Etymology 4

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

Etymology 5

See file.

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