OK

OK is an American English word denoting approval, acceptance, agreement, assent, acknowledgment, or a sign of indifference.

American English, also called United States English or U.S. English, is the set of varieties of the English language native to the United States.

Kirk Franklin - OK by Kirk Franklin

OK is frequently used as a loanword in other languages.

A loanword is a word adopted from one language and incorporated into another language without translation.

KO Home Alone | OK K.O.! Let's Be Heroes | Cartoon Network by Cartoon Network

It has been described as the most frequently spoken or written word on the planet.

The origins of the word are disputed.

As an adjective, OK principally means "adequate" or "acceptable" as a contrast to "bad" ; it can also mean "mediocre" when used in contrast with "good".

It fulfills a similar role as an adverb.

As an interjection, it can denote compliance, or agreement.

In linguistics, an interjection is a word or expression that occurs as an utterance on its own and expresses a spontaneous feeling or reaction.

It can mean "assent" when it is used as a noun or, more colloquially, as a verb.

A noun is a word that functions as the name of some specific thing or set of things, such as living creatures, objects, places, actions, qualities, states of existence, or ideas.

OK, as an adjective, can express acknowledgement without approval.

As a versatile discourse marker or back-channeling item, it can also be used with appropriate voice tone to show doubt or to seek confirmation.