'atrazine' is formed from the chemical-class name 'triazine' (from Neo-Latin/chemical nomenclature), where 'tri-' meant 'three' (referring to three nitrogen atoms in the ring) and '-azine' referred to nitrogen-containing heterocycles.

'triazine' comes from chemical/Neo-Latin usage describing the three-nitrogen ring; the specific name 'atrazine' arose in the 20th century as a trade/chemical name for a particular chloro-s-triazine herbicide and came to denote that compound.

Originally related to the general class of triazine ring compounds, the term 'atrazine' evolved to refer specifically to the widely used 2-chloro-s-triazine herbicide and, by extension, that commercial product and its formulations.