I know from watching old movies that in the U.S., for a time at the dawn of the vacuum tube era, the term "radio" was used to refer to the field of electronics (in addition to the medium of broadcast audio, of course). When did the term "electronics" take over?
Slander! Also, this is probably better in the English Stack Exchange... Anyway Electricity and Electronics and similar works take the root word Elektron in Greek, and apply latin-style adjustments to the end of the word. The "onics" is a suffix of the noun that denote a body of facts, knowledge, or principles. There are many words with this ending.
Many non-english languages such as German use the same word too, like "Elektrik" usually with lots of "k"s in there for good measure. Not sure about the yankees, but i'm certain that every other place has referred to electronics as such, since the dawn of electronics.