Noun: actinoid 'ak-ti,noyd
- Any of a series of radioactive elements with atomic numbers 89 through 103
"Uranium is an actinoid commonly used in nuclear reactors";
- actinide
- Having a radial form
"starfish are actinoid — that is, they are radially symmetrical"
Derived forms: actinoids
See also: actinomorphic, actinomorphous
Encyclopedia: Actinoid