astatine
noun
as·ta·tine ˈa-stə-ˌtēn 
: a radioactive halogen element discovered by bombarding bismuth with alpha particles and also formed by radioactive decay see Chemical Elements Table
Word History
Etymology
Greek astatos unsteady, from a- + statos standing, from histanai to cause to stand — more at stand
First Known Use
1947, in the meaning defined above
Medical Definition
astatine
noun
as·ta·tine ˈas-tə-ˌtēn
: a radioactive halogen element discovered by bombarding bismuth with helium nuclei and also formed by radioactive decay —symbol At
called also ekaiodine
see Chemical Elements Table