The word "до" in Russian translates to "to" or "until" in English. It is commonly used to indicate direction, time, or a limit. For example, you might say "до дома" which means "to the house," showing movement towards a specific location. Additionally, "до" can express a time frame, such as "до завтра," meaning "until tomorrow." This usage helps to set boundaries for actions or events. Overall, "до" is a versatile preposition that plays a crucial role in everyday communication in the Russian language.