toponym 
局所名; トポニーム
1.a place name.
2.a name derived from the name of a place.
Citations for toponym
To christen the inhabitants of his faraway galaxies, George Lucas, the film's creator, made numerous references to some earthly names: Darth Vader (dark water), Luke Skywalker (walks through the sky), Princess Leia (lei -- garland of flowers) and Han Solo (the lone hand). Mr. Lucas's poetry also extends to naming planets. Consider his most prominent toponym, a cold planet named Hoth.