/ ækˈtɪniəm; NAmE / noun
[ U ] ( symb Ac ) a chemical element. Actinium is a radioactive metal.
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WORD ORIGIN
early 20th cent.: from Greek aktis , aktin- ray + -ium , used to form names of metallic elements.
/ ækˈtɪniəm; NAmE / noun
[ U ] ( symb Ac ) a chemical element. Actinium is a radioactive metal.
••
WORD ORIGIN
early 20th cent.: from Greek aktis , aktin- ray + -ium , used to form names of metallic elements.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005