The Vietnamese word "hành tây" means "onion" in English. An onion is a bulbous vegetable that is commonly used in many dishes around the world for its flavor. They can be white, yellow, or red, and they can be eaten raw in salads, cooked in soups and stews, or used to flavor a variety of foods.
While "hành tây" primarily means "onion," the word "hành" alone can refer to other types of onions or even to the action of doing something (as a verb), depending on the context. However, when combined with "tây," it specifically indicates the common onion.