The word "hi" has been around since at least the Middle English period, with the earliest known use dating back to approximately 1475.
While the precise origin is debated, "hi" emerged as a variant or alteration of another word. It's believed to have appeared during the Middle English period (roughly 1150 to 1500). The Oxford English Dictionary (OED) cites its earliest documented appearance as being around 1475, in the text Hunting of Hare. This places the word's age at roughly 549 years old (as of 2024). It's worth noting that this is just the earliest documented use, and the word could have been in spoken usage prior to that.
Therefore, while we can't pinpoint the exact date of its creation, we can confidently say that "hi" is over half a millennium old, at minimum.
