In Japanese, this word means ready. Upon this command from a sensei, karate students assume yoi, or the ready position, one of the first stances learned.

The feet are positioned shoulder-length apart with the toes pointing straight ahead and knees slightly bent. Elbows should nearly touch the sides and the hands should be in a fist at about waist level with the palms facing toward the body and about five inches apart.

From this position, it is easy to quickly assume any other stance.

In Japanese, "yoi" also means "drunk". And, it's also a form of "ii", which means "good". I find it a little funny that the word for drunk is the same as the word for good. However, they do have different kanji.