[thawr-on, thohr-]

noun Chemistry.

a radioactive isotope of radon, produced by the disintegration of thorium. Symbol: Tn; atomic weight: 220; atomic number: 86.

Origin of thoron

First recorded in 1925–30; thor(ium) + -on2 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for thoron

Historical Examples of thoron

  • But the crusaders embarrassed themselves with the siege of the castle of Thoron.

British Dictionary definitions for thoron



a radioisotope of radon that is a decay product of thorium. Symbol: Tn or 220 Rn; atomic no: 86; half-life: 54.5s

Word Origin for thoron

C20: from thorium + -on
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