From BEAM Robotics Wiki
 A Brief History of the Word "Robot"
Back in the year 1920, author Karel Čapek’s wrote his now famous (at least amongst fans of science fiction) play R.U.R. (Rossum's Universal Robots). In 1923 the play was translated from Czech and published in English. Thus the word “robot” was introduced to, and became a part of the language. Although it is widely held that Karel coined the term robot, he credited his brother Josef Capek (a painter and writer) as the true originator of the word.
The word robot (often abbreviated Bot) is derived from the Czech word robota (meaning servitude, forced labour), which itself comes from the root rab meaning “slave”.
It did not take long for the word robot to all but replaced the word Automaton in literature, and in the public mind. This despite the fact that automaton (which had been used prior to that time) generally refers to a mechanical simulacrum of an animal or a human being. Whereas the robots described in R.U.R. are engineered biological constructs similar in concept to the Replicants in Blade Runner, or the Cylons in the new Battlestar Galactica.
 What Is A Robot?
“I can’t define a robot, but I know one when I see one”, Joseph Engelberger
Over the years the word robot has for all intents and purposes become a generic label. As such, it has no single definition, and there is no universally excepted explanation for what differentiates a robot from any other machine.
When a typical fan of science fiction movies hears the word robot, it tends to engender visions of Robbie the Robot, Muffit the robotic daggit, Doctor Who's robot dog K9 and a particularly beloved rolling, whistling trash can.
But the term robot has been used to describe everything from the Mechanical Arms used on assembly lines for moving, welding, and painting parts and assemblies, to Remote Manipulators, to Planetary Rovers and AUVs , and unmanned, remotely operated aircraft (drones) and ground vehicles used by the military, police and search and "search & rescue" personnel.
There are even those who apply the label robot to a dishwasher because it automatically performs a task that would otherwise have to be done manually by a human being.
 A Robot Is...
To most hobbyist however, a robot is: an autonomous, usually mobile machine, that can avoid dangers, deal effectively with objects and conditions it encounters, and perform a given task or tasks without human intervention.
Preferably an autonomous robot should also be completely self sufficient, not requiring a human assistance to replenish or replace its power source, protect it from the family dog, or untangle it from the draperies. It should also be able to determine for itself how best to perform a required task.
The ultimately autonomous robot would not only be able to complete a task given to it by a human, but it would also be able to select and complete tasks of its own choosing.
 External Links
 What Is A Robot