The word 毒药 (dúyào, "poison") is formed by conceptually combining two independent ideas: 毒 (dú), which means "poison" or "toxic", and 药 (yào), which means "medicine" or "drug". It is a direct, logical compound where the first character specifies the dangerous, lethal nature of the second character, effectively creating the meaning of a "drug that is poisonous" or a "toxic substance used as a medicine", historically acknowledging that many potent medicines were, and are, derived from or identical to toxic materials.