- Learn English
-
Learn grammar
-
List of words
-
Study your cards
-
Hang On, Man!
-
Audio Books
-
More apps
- Recent searches
-
actinoid
-
actinometry
-
11th
-
poverty
-
promiscuous
-
starving
-
speaking
-
sex
-
repetitiousness
-
knickknack
- Hide translation
actinium
actinium /ækˈtɪnɪəm/
noun
-
A radioactive element of the actinide series; found in uranium ores
(
Ac
, actinium
, atomic number 89
)
a radioactive element of the actinide series; found in uranium ores
