It depends on the context. In English, "OK" can be used in a variety of situations. ("Are you ok?" "Is it okay if we run by the store real quick?" "It's an okay movie.") Thus, a direct, one size fits all translation of "OK" into Japanese would be stretching it a bit. Here's some contextual "OKs."
1. "Is that okay/Are you okay/all right?" Daijoubu would be the word your looking for. ("Daijoubu desu ka?") Daijoubu is a fairly versatile word, and can be used much like the English "OK" or "All right," but doesn't quite cover it all.
2. "Is it/that okay?" Ii desu ka.
I guess you could say 'sufficient/okay'.eg. Ikaga desuka? Is this okay?
What is the word 'Honorable' when translated from English to Japanese.
The word sick when translated from English to Japanese is mukatsuku.
The word 'maple' when translated from English to Japanese is カエデ.
The word drag when translated from English to Japanese is hipparu.
The word crown when translated from English to Japanese is oukan or kuraun.
The word listener when translated from English to Japanese is kikite or risuna.
There is no equivalent word in Japanese for the English word "a."
The word 'champion' when translated from English to Japanese is ăăŁăłăăȘăł (champion).
Of= No in Japanese
There's no such word in Japanese.
Tsuki when translated from English to Japanese means "moon".