Radius’ is a latin word that means spoke of a wheel, ray of light, radiate
Radicitus means … 1) at the root, 2) by the roots, utterly, completely
From Wikipedia
The term “radio” is derived from the Latin word “radius”, meaning “spoke of a wheel, beam of light, ray”. It was first applied to communications in 1881 when, at the suggestion of French scientist Ernest Mercadier, Alexander Graham Bell adopted “radiophone” (meaning “radiated sound”) as an alternate name for his photophone optical transmission system. However, this invention would not be widely adopted.