Loresworld was a planet where, in 2369, Lore and his rogue Borg faction planned their conquest of the galaxy by synthetic lifeforms. Their base was located in a hilly region of the planet.
The planet had an unusual level of EM activity in the magnetosphere, which interfered with sensors, and had at least two moons. (TNG: "Descent", "Descent, Part II")
The planet was not named in the episode; rather, the name came from StarTrek.com, which also described it as an M-class planet.