tho·ron 
(thôrŏn′)
(thôrŏn′)n.
A radioactive isotope of radon, Rn-220, having a half-life of 54.5 seconds and produced by the disintegration of thorium.
[THOR(IUM) + -ON2.]
- Catharism
- Catharist
- catharsis
- cathartic
- Cathay
- cathead
- cathect
- cathectic
- cathedra
- cathedral
- cathedral ceiling
- cathepsin
- Cather
- Catherine
- Catherine
- Catherine
- Catherine de' Medici
- Catherine de Médicis
- Catherine I
- Catherine II
- Catherine of Aragon
- Catherine of Braganza
- Catherine of Siena
- "Catherine the Great."
- catherine wheel