The Chinese word 病毒 (bìngdú, meaning "virus") is formed by combining two meaningful characters into a single conceptual unit. The first character, 病 (bìng), means "illness" or "disease", establishing the category of harm or sickness. The second character, 毒 (dú), means "poison" or "toxin", specifying the nature of the agent as a poisonous, invasive substance. Together, they create a direct and logical compound meaning "sickness poison", visually and conceptually representing the idea of a pathogenic entity that causes disease.