Radio

For no particular reason, my brain decided it needed to know why it's called a "radio", like Gourmet Chef Elaine's Sony shown below.  At first, I figured it might be an acronym like "laser" or "scuba", but that's not it.  It's derived from the Latin root word "radius," which means a spoke of a wheel or a beam of light, and words like "radiate", "radial", and "radius".  

At first, "radio" was used as a prefix, for example, a "radiophone" or "radio-conductor", anything that moved in "rays" or "radiated" energy.  While initially called "Wireless Telegraphy" and preferred across the British Empire, "Radio" was the preferred term in Continental Europe and the United States.  By the early 1900s, "radio" was crowned the worldwide winner, although still as a prefix.

By the 1920s, as broadcasting became a massive public medium for music and news, people dropped the "telegraphy" or "telephony" suffixes. The shortened version, radio, became the standard noun we use today.