"Achoo" is a common exclamation that signifies a sneeze. The sound of "achoo" is universal and recognized worldwide. Although "achoo" is the most commonly used term to describe a sneeze, there are several other synonyms for the word. For instance, some people say "atishoo," "ach-oo," "achoof," "hachoo," "ha-chi," and "ha-tchi." The sound of "achoo" may differ based on cultural, regional, and individual accents. However, the function remains the same; it is a sound that helps to expel germs and irritants from the nose. Regardless of the synonym used when someone says, "achoo," it's an automatic response to anticipate a series of sneezes.