What is the true definition of a planet.?

Pluto has been eliminated as a true planet. Others say that the gas giants are not truly planets because they lack a solid form. Is it because it orbits the sun or because it is solid or both.What is the true definition of a planet.?
According to the IAU, it is as follows:





A ';planet'; is a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.What is the true definition of a planet.?
There are two mainly accepted definitions for a planet:





There is the definition set by the IAU, which was written in 2006 and edited in 2008. Basically, all planets must meet the following criteria:





1. They must orbit a star.


2. They must be the largest object in their orbital path.


3. They must be in a spherical shape as a result of their self created gravity and pressure.


4. They must have a core that is not currently undergoing nuclear fusion.


5. It must have a clear orbital path, free from smaller objects like asteroids. This is where pluto meets its demise. It is located in an asteroid belt. Poor pluto...





And then you have the ';dynamic'; definition of a planet. It must:





1. Be in a spherical shape.


2. It nust not have obtained nuclear fusion at its core.





Now, according to the IAU's definition, pluto isn't a planet. But if we use the dynamic definition it is... Our moon is also a planet. Jupiter's spherical moons are.


Personally, I prefer the IAU definition and it is also the most widely accepted definition.
Gas giants have solid, albeit typically very small, but still solid cores.





Planets are what people have decided to call planets. Much in the same way that continents are whatever masses of land that people decided to call continents. The IAU is ridiculous in regards to this matter.