Dictionary.com
definitions
  • synonyms

mesothorium

[mez-oh-thawr-ee-uh m, -thohr-, mes-, mee-zoh-, -soh-]
See more synonyms for mesothorium on Thesaurus.com
noun Chemistry.
  1. one of two radioactive decay products of thorium, an isotope of radium or actinium.
Show More
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for mesothorium

mesothorium

noun
  1. physics obsolete either of the two radioactive elements which are decay products of thorium. Mesothorium I is now called radium-228. Mesothorium II is now called actinium-228
Show More
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012