It is originally from the Greek but moved into contemporary usage back in 1948.
“Cyber” is a prefix used to describe a person, thing, or idea as part of the computer and information age. Taken from kybernetes, Greek for “steersman” or “governor,” it was first used in cybernetics, a word coined by Norbert Wiener and his colleagues. Common usages include cyberculture, cyberpunk, and cyberspace.

Cybernetics is a word coined by group of scientists led by Norbert Wiener and made popular by Wiener’s book of 1948, Cybernetics or Control and Communication in the Animal and the Machine. Based on the Greek “kybernetes,” meaning steersman or governor, cybernetics is the science or study of control or regulation mechanisms in human and machine systems, including computers.

Cyberpunk is a sensibility or belief that a few outsiders, armed with their own individuality and technological capability, can fend off the tendencies of traditional institutions to use technology to control society. The term, combining “cyber” and punk, possibly originated in 1980 with Bruce Bethke’s short story, “Cyberpunk.” An editor of Isaac Asimov’s Science Fiction Magazine, Gardner Dozois, is credited with associating the word with a literary movement that includes the science fiction of William Gibson and Neal Stephenson.
The alt.cyberpunk.FAQ lists several categories of groups associated with cyberpunk:
hacker, who represent the best kind of cyberpunk
cracker, who attempt to break into computer systems
phreak, who attempt to break into telephone systems
Cypher-punks, who attempt to break codes and foil security systems
Additional groups include “transhumans,” who attempt to exploit technology to increase life expectancy and human potential and “extropians,” a kind of libertarian group that believes in something called “spontaneous order.” The writer of the alt.cyberpunk.FAQ indicates that some people believe cyberpunk to be (intrinsically) undefinable and that anyone claiming to be a “cyberpunk” will likely be laughed off their Usenet newsgroup.

Cyberspace is the total interconnectedness of human beings through computers and telecommunication without regard to physical geography.
William Gibson is sometimes credited with inventing or popularizing the term by using it in his novel of 1984, Neuromancer.

Source: http://searchsoa.techtarget.com/definition/cyber