Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “key”

See all translations

key

noun [C]
 
 
/kiː/
FOR LOCKS A1 a piece of metal cut into a particular shape and used for locking things such as doors, or for starting an engine: I've lost my car keys.Locking and bolting
METHOD B1 a way of explaining or achieving something: Hard work is the key to success.Ways of achieving things
KEYBOARD B2 one of the parts you press with your fingers on a keyboard or musical instrument to produce letters, numbers, or to make a soundComputer hardwareKeyboard instruments
MUSIC a set of musical notes based on one particular note: the key of D majorTechnical music terms
SYMBOLS a list that explains the symbols on a map or pictureMaps and map-makingSigns, signals and symbolsSpecific signs and symbols
ANSWERS A2 a list of answers to an exercise or game →  See also under lock and key Solving and solutions
(Definition of key noun from the Cambridge Learners Dictionary © Cambridge University Press)
Add Cambridge dictionaries to your browser to your website

Definitions of “key” in other dictionaries

Word of the Day

be as cold as ice

to be extremely cold

Word of the Day

Let’s celebrate! (words and phrases for parties)

by Kate Woodford,
December 17, 2014
​​​ With Christmas and New Year almost upon us, we thought it a good time to look at the language of parties and celebrations. First, let’s start with the word ‘party’ itself. To have or throw a party or, less commonly, to give a party is to arrange a party: We’re having a

Read More 

cinderella surgery noun

December 15, 2014
cosmetic surgery to the feet We have all heard of people having nose jobs, boob jobs and liposuction – but now a new trend growing in popularity in America: Cinderella surgery.

Read More