'pyrimidine-related' originates from the noun 'pyrimidine' (Neo-Latin/19th-century scientific coinage 'pyrimidinum') combined with English 'related' (from Latin 'relatus' via Old French 'relater'), where 'pyrimidine' names a class of nitrogen-containing heterocyclic compounds.

'pyrimidine' was coined in modern scientific Latin/European chemical literature in the 19th century (e.g. German/French forms like 'pyrimidin') by analogy to names such as 'pyridine' and was adopted into English; 'related' is the past participle of 'relate' (from Latin 'referre'/'relatus'), and the compound adjective arose by straightforward combination of the noun with 'related'.

Initially the elements simply identified the chemical class and a relation; over time the compounded adjective came to be used as a concise technical term meaning 'pertaining to or associated with pyrimidines'.