Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

  

key

 
 
/kiː/ noun [C]

Definition

FOR LOCKS 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.
METHOD a way of explaining or achieving something: Hard work is the key to success.
KEYBOARD one of the parts you press with your fingers on a keyboard or musical instrument to produce letters, numbers, or to make a sound
MUSIC a set of musical notes based on one particular note: the key of D major
SYMBOLS a list which explains the symbols on a map or picture
ANSWERS a list of answers to an exercise or game → See also under lock and key
(Definition of key noun from the Cambridge Learner's Dictionary © Cambridge University Press)

Word of the Day

throw caution to the wind/winds

to do something without worrying about the risk or negative results

Word of the Day

Blog

Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More