A nice little article on the etymology of Cyber.
It all started with “cybernetics,” an obscure term popularized by a mathematician named Norbert Weiner in the 1940s. For his groundbreaking book Cybernetics, Weiner borrowed the ancient Greek word “cyber,” which is related to the idea of government or governing. Indeed, the only time the word cybernetics had appeared before was in a few works of political theory about the science of governance.
In his writing, Weiner described what was at the time a pretty futuristic idea — that one day there would be a computer system that ran on feedback. Essentially, it would be a self-governing system. And for a long time, cybernetics remained the purview of information theorists like Weiner, and early computer programmers.
Science fiction author Pat Cadigan, whose novel Mindplayers is a cyberpunk classic, recalled that her first encounter with “cyber” was of a decidedly Weinerish variety. She told io9 that the first time she heard the term was when she was in high school in 1967, and somebody mentioned cybernetics. “I asked what cybernetics was. ‘It has to do with computers,’ was the answer. My eyes glazed over. For years, that was the only word I knew with the prefix ‘cyber’ in it.”