Pathogen = Greek páthos (suffering) + -genēs (producing), literally 'disease-producer.' PIE *kwent(h)- + *ǵenh₁-. Coined during the germ theory revolution. Connects the pathos family (empathy, sympathy, apathy, psychopath) to the -gen family (collagen, genocide, gene, oxygen).
A microorganism — bacterium, virus, or fungus — that causes disease in a host organism.
From Greek παθογόνος (pathogónos), a compound of πάθος (páthos, "suffering, experience, emotion") and -γενής (-genḗs, "born of, producing"), from γίγνομαι (gígnomai, "to come into being"). The πάθος element traces to PIE *kwent(h)- ("to suffer, endure"), which also yields Old English cwellan ("to kill") and Lithuanian kentėti ("to suffer"). The -genḗs component derives from PIE *ǵenh₁- ("to beget, give birth"), one of the most productive roots