The story
frozen+star * (stellar black hole, black hole alternative): From relativity predicting the passage of time slowing to a stop as the star collapses through its event horizon, "freezing" time and the star. * (Population 0 star): From the existence of frozen volatiles, such as water ice, existing in the atmosphere and on the surface of such a star
Etymology from Wiktionary, CC BY-SA 4.0.