The supposed material composed entirely of neutrons that composes a neutron star(noun)
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Use "neutronium" in a sentence
"Yesterday, I did not see my apartment between 8 am and 10: 30 pm, and the cat is letting me know about it (Cat, take your tiny neutronium paws off my bruised shin)."
"No indeed, these black holes are the implacable and hungry servants of the Beast, an energy being contained in a neutronium exoskeleton, who was spontaneously generated from the warping of space near the event horizon of Sagittarius A, that 300-million-solar mass black hole known as the Maw of the Milky Way."
"Cat: Monkey, can I walk across your nice soft abdomen with my hard neutronium paws??"