raring to go

[darkoshi]

This expression was familiar, but I may not have seen it in writing before today.

Raring: adjective Informal.
very eager or anxious; enthusiastic: raring to go.

I expected it to be spelled "rearing to go", similar to the phrase "to rear up" (like a horse)

In fact, "raring" does derive from the term "rear" as in "rear up":
https://www.etymonline.com/search?q=raring

In fact, both spellings are acceptable:
https://www.csmonitor.com/The-Culture/In-a-Word/2020/0723/Are-horses-rearing-to-go-or-raring-to-go

Based on the number of search results listed by Google, the "raring" spelling is more than 5 times as common, however.