plutonic

1. (Greek mythology, Roman mythology) Synonym of Plutonian (“of or relating to Pluto, the Greek and Roman god of the underworld; demonic, infernal”).Synonyms: PlutonianGreekRoman

2. (by extension) Synonym of Plutonian (“of, relating to, or having characteristics associated with the underworld; dark, gloomy; mournful”).Examples: "a dark, handsome lady, of no little majesty, and rather like a plutonic Madonna"Synonyms: Plutonianbroadly

3. (by extension, geology, mineralogy) Of or pertaining to rocks formed deep in the Earth's crust, rather than by volcanoes at the surface of the Earth.Examples: "These cliffs, I may remark, are basaltic, and therefore plutonic."Synonyms: abyssal, intrusive, Plutonianbroadly

4. (by extension, geology, historical) Of, pertaining to, or supporting plutonism (“the theory that the rocks of the Earth were formed in fire by volcanic activity, with a continuing gradual process of weathering and erosion, then deposited on the sea bed, re-formed into layers of sedimentary rock by heat and pressure, and raised again”).Synonyms: Plutonianbroadlyhistorical