Sentence:  Neptune has a faint ring system and 14 known moons. The largest of these is Triton, which contains over 90% of the mass of all the <WSD>Neptunian</WSD> moons, and is the only <WSD>Neptunian</WSD> moon that's spherical. 
Meaning of the word marked with <WSD> tags:  Of or pertaining to the planet Neptune.