Coined 1903 by Johannsen from Greek 'genos' (kind) + 'typos' (type) — distinguishing genetic makeup from observable traits.
The genetic constitution of an organism, as distinguished from its physical characteristics (phenotype).
From German Genotypus, coined in 1903 by Danish botanist Wilhelm Johannsen, combining Greek γένος (génos, "race, kind, offspring") and τύπος (týpos, "blow, impression, model, type"). Γένος derives from PIE *ǵenh₁- ("to beget, give birth, produce"), one of the most productive roots in Indo-European, yielding: Latin genus, gēns ("clan"), generāre ("to beget"); Greek γίγνομαι (gígnomai, "to be born"), γένεσις (génesis); Sanskrit jánas ("race"), jā- ("to be born"); and English kin, kind, and king (the latter literally "son of the people"). Τύπος comes from PIE
Johannsen coined 'genotype,' 'phenotype,' and 'gene' in rapid succession between 1903 and 1909 — three words that became the foundation of all modern genetics. He deliberately chose Greek roots to give the new science an international vocabulary, knowing that Greek-based terms would be recognizable across European languages.