Where does “hipopotamus” come from?

hipopotamus (Welsh) comes from English hippopotamus, from Latin hippopotamus, from Ancient Greek ἱπποπόταμος, from Ancient Greek ἵππος, from Proto-Hellenic íkkʷos, from Proto-Indo-European h₁éḱwos, from Proto-Indo-European h₁oh₁ḱu- — swift.

Ancestry of “hipopotamus”, step by step

StepLanguageWordMeaning
1EnglishhippopotamusA large, semi-aquatic, herbivorous African...
2Latinhippopotamusa hippopotamus
3Ancient Greekἱπποπόταμοςhippopotamus
4Ancient Greekἵπποςa horse, a mare; cavalry, horsemen
5Proto-Hellenicíkkʷoshorse
6Proto-Indo-Europeanh₁éḱwosstallion, horse
7Proto-Indo-Europeanh₁oh₁ḱu-swift
Every word from Proto-Indo-European h₁oh₁ḱu-Every word from Proto-Indo-European h₁éḱwosEvery word from Proto-Hellenic íkkʷos