Is OK a real word?

Is OK a real word? OK (spelling variations include okay, O.K., ok and Ok) is an English word (originally American English) denoting approval, acceptance, agreement, assent, acknowledgment, or a sign of indifference. OK is frequently used as a loanword in other languages.

OK (spelling variations include okay, O.K., ok and Ok) is an English word (originally American English) denoting approval, acceptance, agreement, assent, acknowledgment, or a sign of indifference. OK is frequently used as a loanword in other languages.