astatine Syllabification: (as·ta·tine)Pronunciation: /ˈastəˌtēn, -tin/Definition of astatine noun the chemical element of atomic number 85, a radioactive member of the halogen group. Astatine was first produced by bombarding bismuth with alpha particles, and it occurs in traces in nature as a decay product. (Symbol: At)Origin: 1940s: from Greek astatos 'unstable' + -ine4astatine in other Oxford dictionaries Definition of astatine in the British & World English dictionary
