The word "vain" is an adjective that describes someone who is excessively proud of their appearance, abilities, or achievements. It can also refer to actions or efforts that are futile or without success. For example, a person who constantly seeks validation for their looks or accomplishments, often to an exaggerated extent, can be described as vain. Additionally, when an endeavor is in vain, it means that it yields no results or is fruitless.
The word "vain" comes from the Latin word "vanus," meaning "empty" or "void." This evolved into the Old French "vain," which influenced the Middle English form, ultimately leading to the modern English usage. The connection with emptiness reflects the idea of emptiness in pride or lack of substance in vain efforts.