Latin word for horse
Hippo. The word hippopotamus literally means river horse.
equus. I believe it is.
Classical Latin: equus Vulgar Latin: caballus
The classical word is equus.
related to the English wiord equine and equestrian. That's to help you remember it.
The word caballus originally meant "an inferior-quality horse; a nag," but became the general word for horse in the common speech.