actinium [noun]

Definition of actinium:

a radioactive element of the actinide series; found in uranium ores

Synonyms of actinium:

● Atomic number 89

● Ac

● Element

● Alternating current

● Atomic number

● Chemical element

● Silver


Opposite/Antonyms of actinium:

● Software

● Curve


Sentence/Example of actinium:

The element has since been found in nature as a small constituent of the natural decay of actinium.