What is "actinoid"

Actinoid \Ac"tin*oid\, a. [Gr. ?, ?, ray + -oid.] Having the form of rays; radiated, as an actinia.

a. Having the form of rays; radiated, as in the species of the family ''(taxlink Actiniidae family noshow=1)''. n. (context inorganic chemistry English) actinide

1. adj. having a radial form; "starfish are actinoid--that is, they are radially symmetrical"

2. n. any of a series of radioactive elements with atomic numbers 89 through 103 [syn: actinide, actinon]