Setting aside the whole "demote Pluto" and "dwarf planet" aspects, I find it amusing that we use the same term for small rocky Mercury (2,440 km radius, 5% of Earth's mass) and immense gaseous Jupiter (69,000 km radius, over 300 times Earth's mass). Only we don't, of course. Jupiter is a gas giant, while Mercury is a rocky planet, or iron planet; there's a lot of 'planet' terminology.

https://en.wikipedia.org/wiki/List_of_planet_types