The word 亚硝胺 is formed by combining three characters: 亚, which in chemistry denotes a secondary or reduced state, often associated with nitrous acid (亚硝酸); 硝, derived from terms like 硝酸 (nitric acid) and here representing the nitroso component; and 胺, meaning amine. The sequence 亚硝 together specifies the nitroso group, and when followed by 胺, it creates the term for nitrosamine, a compound where a nitroso group is attached to an amine.