Actinium

Definition:

• (n.) A supposed metal, said by Phipson to be contained in commercial zinc; -- so called because certain of its compounds are darkened by exposure to light.

Compare actinium with other words:

actinium vs. actinoid

actinism vs. actinium

actinium vs. ore

actinium vs. uranium

actinium vs. element

actinium vs. chemical

actinium vs. radioactive

actinium vs. metallic