actinon

US: (ak′tə non′)

WordReference Random House Unabridged Dictionary of American English © 2025

ac•ti•non  (ak′tə non′), n. [Chem.]

1. Chemistry a chemically inert, gaseous, short-lived isotope of radon that is a member of the actinium series. Symbol: An;
   at. no.: 86;
   at. wt.: 219. Also called actinium emanation. 

• Neo-Latin; see actinium, -on²
• 1925–30

Collins Concise English Dictionary © HarperCollins Publishers::

actinon / ˈæktɪˌnɒn/ noun

1. another name for actinide

Etymology: 20th Century: New Latin, from actinium + -on