from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A celestial body that orbits the sun and is large enough to assume a nearly round shape, but that does not clear the neighborhood around its orbit and is not a satellite of a planet. See Usage Note at planet.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any astronomical body which has achieved hydrostatic equilibrium (which is the shape a body of water would take, as opposed to a small Solar System body), orbits the Sun (as opposed to a moon), and has not "cleared its neighbourhood" of competing bodies (as opposed to a planet).
Sorry, no etymologies found.