pluˈton noun (geology)

A mass of rock which has solidified below the earth's surface

Plutoˈnian adjective

1. Of Pluto
2. Of the underworld

Plutonic /-tonˈik/ adjective

1. Of Pluto
2. (also without cap) hypogene, deep-seated, relating to or formed under conditions of subterranean heat (geology)
3. Plutonist

Plutonism /plooˈtən-izm/ noun

Pluˈtonist noun and adjective (obs geol)

Vulcanist

plutōˈnium noun

An artificially produced radioactive transuranic element (symbol Pu; atomic no 94), named as next after neptunium (93; Pluto being regarded at the time as the planet beyond Neptune), having many isotopes, the fissile isotope²³⁹Pu being particularly important in the production of nuclear power