actinide

[ ak-tuh-nahyd ]

noun

, Chemistry.

1. any element of the actinide series.

actinide

/ ˈæktɪˌnaɪd /

noun

1. a member of the actinide series Also calledactinon

actinide

/ ăk′tə-nīd′ /

1. Any of a series of chemically similar metallic elements with atomic numbers ranging from 89 (actinium) to 103 (lawrencium). All of these elements are radioactive, and two of the elements, uranium and plutonium, are used to generate nuclear energy.
2. See Periodic Table

Word History and Origins

Origin of actinide¹

1940–45; actin- + -ide, on the model of lanthanide

Word History and Origins

Origin of actinide¹

C19: from actino- + -ide