Definition of radon noun from the Oxford Advanced Learner's Dictionary

 

radon

 noun
noun
BrE BrE//ˈreɪdɒn//
 
; NAmE NAmE//ˈreɪdɑːn//
 
[uncountable](symbol Rn)
 
jump to other results
a chemical element. Radon is a radioactive gas used in the treatment of diseases such as cancer. Word Origin early 20th cent.: from radium, on the pattern of argon.
See the Oxford Advanced American Dictionary entry: radon