- Learn English
-
Learn grammar
-
List of words
-
Study your cards
-
Hang On, Man!
-
Audio Books
-
More apps
- Recent searches
-
ou
-
codpiece
-
clock face
-
incur
-
island
-
absolute ceiling
-
a fortiori
-
frown
-
reticent
-
prandial
- Hide translation
actinide
actinide /ˈækˈtɪnˌaɪd/
noun
-
Any of a series of radioactive elements with atomic numbers 89 through 103
(
actinide
, actinoid
, actinon
)
any of a series of radioactive elements with atomic numbers 89 through 103