English Reference
noun · adjective · verb

key

n. · adj. · v.
US /ˈki/ UK /kˈiː/ key UK spelling keyed

  1. 01 A1 Beginner

    n.a small piece of metal used to open a lock or start a car.

    n.a metal instrument specifically shaped to operate the bolt of a lock.

    Simple

    He reached into his pocket and realized he had left his house keys at the office.

    In context

    The landlord handed over a heavy ring of keys, explaining which ones accessed the main gate and which opened the basement storage.

    openerlatchkey
  2. 02 A2 Elementary Computing

    n.one of the buttons you press on a computer, phone, or piano.

    n.any of the buttons or levers on a keyboard, typewriter, or musical instrument that are depressed to produce a character or sound.

    Simple

    If the screen freezes, try pressing the escape key to close the program.

    In context

    The pianist's fingers flew across the ivory keys, executing the complex concerto with remarkable precision and emotional depth.

  3. 03 B1 Intermediate

    n.the most important thing that helps you understand or achieve something.

    n.a crucial factor or explanation that provides a solution or means of understanding.

    Simple

    Hard work and a bit of luck were the keys to her success in business.

    In context

    Identifying the primary motive of the suspect proved to be the key to solving the long-running investigation.

  4. 04 B1 Intermediate

    n.a list of symbols or answers that explains what things mean on a map or in a book.

    n.an explanatory list of symbols used in a map, table, or chart; also a set of answers to a test.

    Simple

    Check the key at the bottom of the map to see what the different colors represent.

    In context

    The textbook includes an answer key in the back so students can check their progress on the practice exercises.

  5. 05 B2 Upper Intermediate Music

    n.a set of musical notes that a piece of music is based on.

    n.a group of notes based on a particular note and comprising a scale, serving as the harmonic foundation of a composition.

    Simple

    The song is written in the key of C major, so it sounds quite happy.

    In context

    The singer requested a transposition because the original key was slightly outside her comfortable vocal range.

    scaletonality
  6. 06 C1 Advanced American English

    n.a small, low island, especially in the Caribbean or near Florida.

    n.a low-lying island or reef, often composed of coral or sand.

    Simple

    We spent our vacation exploring the different keys along the coast of Florida.

    In context

    The archipelago consists of several uninhabited keys that serve as vital nesting grounds for local seabird populations.

  7. 07 B1 Intermediate

    adj.the most important or necessary part of something.

    adj.of paramount importance; fundamental or essential to a system or result.

    Simple

    Education is a key part of a child's development.

    In context

    The CEO identified three key areas where the company needed to improve to remain competitive in the global market.

  8. 08 B2 Upper Intermediate Computing

    v.to type information into a computer or device.

    v.to enter data into a computer system using a keyboard.

    Simple

    You need to key in your password before you can access the files.

    In context

    The clerk spent the entire afternoon keying in the data from the paper applications into the new digital database.

    Usage

    Often used as the phrasal verb 'key in'.

  9. 09 B2 Upper Intermediate Informal

    v.to damage a car by scratching the paint with a key.

    v.to vandalize the bodywork of a vehicle by scratching it with a metal key.

    Simple

    He was angry and decided to key his ex-girlfriend's car.

    In context

    The security footage showed a hooded figure walking past the parked vehicles and deliberately keying the side panels of the luxury sedan.

    scratchvandalize

Usage key role · key part · key factor

This entry
Level A1 · Beginner
Frequency Very common
Updated