[1] : The Collaborative International Dictionary of English v.0.48

plutonic \pluton"ic\, a. cf. f. plutonique. see pluto.
   1. of or pertaining to pluto; plutonian; hence, pertaining to
      the interior of the earth; subterranean.
      1913 webster

   2. of, pertaining to, or designating, the system of the
      plutonists; igneous; as, the plutonic theory.
      1913 webster

   plutonic action geol., the influence of volcanic heat and
      other subterranean forces under pressure.

   plutonic rocks geol., granite, porphyry, and some other
      igneous rocks, supposed to have consolidated from a melted
      state at a great depth from the surface. cf. intrusive
      rocks, under intrusive.

   plutonic theory. geol. see plutonism.
      1913 webster
see also:
pluto plutonic action plutonic rocks intrusive rocks intrusive plutonic theory 
plutonism 

[2] : WordNet (r) 2.0

plutonic
     adj : of igneous rock that has solidified beneath the earth's
           surface; granite or diorite or gabbro syn: irruptive,
            eruptive
see also:
irruptive eruptive 

Plutonic >> P Words
Plutonic, definition of term: Plutonic
plutonic_pag1.html

Plutonic Rocks >> P Words
Plutonic Rocks, definition of term: Plutonic Rocks
plutonic+rocks_pag1.html

Plutonic Rock >> P Words
Plutonic Rock, definition of term: Plutonic Rock
plutonic+rock_pag1.html