plutonic
[adjective]
Synonyms: infernal, chthonian, chthonic, Hadean, plutonian, sulphurous, Tartarean, avernal, cimmerian, hellish, pandemoniac, stygian

[TahlilGaran] English Synonym Dictionary ▲

plutonic adjective & noun. [plu:'tɒnɪk] L18.
[formed as PLUTONIAN + -IC.]
A. adjective.
1. Geology. Pertaining to or involving the formation of rocks at great depths in the earth's crust; abyssal; spec. pertaining to or designating igneous rocks formed at great depths by intense heat. Also, designating, pertaining to, or advocating Plutonism. L18.

2. Belonging to or resembling Pluto; Plutonian. E19.
b. noun. Geology. In pl. Plutonic rocks. M19.

[TahlilGaran] English Dictionary ▲