The word "纳税人" is formed by sequentially combining three characters: 纳, which means "to pay" or "to hand in"; 税, which means "tax"; and 人, which means "person". Together, they create a literal compound meaning "tax-payer", where 纳 modifies 税 to form the action "pay tax", and this phrase then modifies 人 to specify the person who performs that action.