It's also a god in Chinese mythology.

Do the Trojan asteroid clusters in Jupiter’s L4 and L5 points still count as “clearing its orbit”?

What if there were a second planet-sized body there?

I would say in that example:

• Jupiter is the dominant mass making it be the planet.
• Anything in the Lagrangian points would not be planets specifically because anything in those points are there because of Jupiter and its orbit, not in spite of it.

There are mathematical formulae for defining it and the dwarf planets have orders of magnitude lower values in comparison to planets: https://en.wikipedia.org/wiki/Clearing_the_neighbourhood

Clearing the orbit is a very shorthand version of the meaning. If it was literal, nothing could be a planet as there's always something in every orbital path. It means the planet is massive enough to be the dominant thing within its orbit.

If the coin is so big that you don't notice the garbage, it's money. If you have to sift through the garage to find the coin, it's just worthless loose change.

A forged coin isn't money despite seeming like it is at first glance.