'thermogenic' originates from Greek elements: 'thermo-' from Greek 'thermē' meaning 'heat' and '-genic' from Greek 'genēs' (via Latin/Modern scientific formation) meaning 'producing' or 'originating'.

'thermogenic' developed in scientific Latin/Modern English from Greek compound forms such as Greek 'thermogenēs' (literally 'heat-producing') and entered English usage via New/Modern Latin and 19th/20th-century scientific vocabulary.

Initially it meant 'producing heat' in a literal sense; over time it retained that core meaning while extending to specialized senses (e.g., metabolic heat production, geologic origin by heat).