Noun
English Wikipedia has an article on:radionWikipedia
radion (plural radions)
(physics) The radius modulus of an extra dimension in a compactification. Coined in 1998 by Nima Arkani-Hamed, Savas Dimopoulos, and John March-Russell in the paper "Stabilization of Sub-Millimeter Dimensions: The New Guise of the Hierarchy Problem".