Key has 28 different meanings across 4 categories:
Noun · Verb · Adjective · Proper Noun
metal device shaped in such a way that when it is inserted into the appropriate lock the lock's mechanism can be rotated
"He fumbled for his car keys until he finally found the right one, slipped it into the ignition, and turned it to start the engine."
United States lawyer and poet who wrote a poem after witnessing the British attack on Baltimore during the War of 1812; the poem was later set to music and entitled `The Star-Spangled Banner' (1779-1843)
"After hearing the anthem played at the stadium, many fans mistakenly assumed it honored Francis Scott Key as a musical composition rather than remembering him as the poet who inspired its lyrics during the War of 1812."
a coral reef off the southern coast of Florida
"The tour boat anchored near the Key to let passengers swim in the clear blue water."
a list of words or phrases that explain symbols or abbreviations
"The chart includes a key to help readers understand what each symbol represents."
a generic term for any device whose possession entitles the holder to a means of access
"a safe-deposit box usually requires two keys to open it"
a lever (as in a keyboard) that actuates a mechanism when depressed
"When I pressed the key on my mechanical keyboard, it clicked satisfyingly and typed the letter onto the screen."
An object designed to open and close a lock.
"The police seized several keys at the party, which were small packets containing kilograms of cocaine cut into single doses."
One of a string of small islands.
Alternative form of quay.
Clipping of kilogram (especially of a recreational drug)
In plain English: A key is a small metal tool with notches that you put into a lock to turn it and open something.
"He lost his house key and was locked out all night."
Usage: Use this term only when referring to a small amount of illicit drugs, not for physical objects like door keys or musical instruments. In all other everyday situations, the word means a metal tool used to unlock something or a vital part of a system.
vandalize a car by scratching the sides with a key
"His new Mercedes was keyed last night in the parking lot"
regulate the musical pitch of
"The pianist spent hours at the piano key to tune the instrument before the concert."
To fit (a lock) with a key.
"The locksmith arrived to key our front door after we lost the original lock and its matching keys."
In plain English: To key means to press down on keys on a keyboard or piano to make sounds or letters appear.
"The artist will key the signature into the official record before the deadline."
Usage: Do not use "key" to mean unlocking a door or starting a machine; instead, use it only when referring to entering data into a computer program or securing a document with a password. The correct verb for physically turning a lock is "unlock."
serving as an essential component
"a cardinal rule"
"the central cause of the problem"
"an example that was fundamental to the argument"
"computers are fundamental to modern industrial structure"
Indispensable, supremely important.
"The new security protocol is a key factor in keeping our company's data safe from hackers."
In plain English: Key means something that is very important or essential to a situation.
"The key ingredient in this recipe is fresh basil."
Usage: Use "key" as an adjective to describe something that is absolutely essential or plays a critical role in a situation, such as a key factor in success. It often appears before a noun like "key ingredient" to emphasize that the item cannot be overlooked.
A surname.
"Sarah Key's family has lived on that coastal road for three generations."
The word "key" comes from Old English cǣġ, which originally meant a key, solution, or experiment. Its ultimate origin is uncertain, though it likely traveled through Anglo-Frisian and Proto-West Germanic before entering Middle English.