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.]
- stratal
- strategic
- strategical
- strategically
- strategics
- strategist
- strategize
- strategy
- Stratford
- Stratford-on-Avon
- Stratford-upon-Avon
- strath
- strathspey
- strati
- strati-
- straticulate
- straticulation
- stratification
- stratified charge engine
- stratiform
- stratify
- stratigraphic
- stratigraphical
- stratigraphically
- stratigraphy