n. [ Cf. F. plutonisme. ] The theory, early advanced in geology, that the successive rocks of the earth's crust were formed by igneous fusion; -- opposed to the Neptunian theory. [ 1913 Webster ]
English-Thai: NECTEC'sLexitron-2 Dictionary [with local updates]NECTEC Lexitron Dictionary EN-TH
(n)a solid silvery grey radioactive transuranic element whose atoms can be split when bombarded with neutrons; found in minute quantities in uranium ores but is usually synthesized in nuclear reactors; 13 isotopes are known with the most important being plutonium 239, Syn.atomic number 94, Pu
(n)a highly fissionable isotope of plutonium that is used in atomic weapons and as a reactor fuel; produced by irradiating uranium 238 with slow electrons