Definition of "Plutonic"
Plutonic
/pluːˈtɒnɪk/
adjective
comparative more Plutonic, superlative most Plutonic
(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”).