noun. Any of a series of chemically similar, radioactive elements with atomic numbers ranging from 89 (actinium) through 103 (lawrencium).

noun. Any of the 14 radioactive elements of the periodic table that are positioned under the lanthanides to which they have similar chemistry.

noun. any of a series of radioactive elements with atomic numbers 89 through 103

"They do, however, create actinide-free waste that is much less radioactive, with a half-life of a couple of hundred years (as opposed to tens of thousands of years for LWR waste)."

americium  curium  neptunium  plutonium  protactinium  

group  grouping  

5b  anti-seize  anticholinesterase  best-of-seven  diazo-