Overview. Caffeine is a chemical primarily found in coffee and tea, but which also appears in various sodas, sports drinks and foods. It is a stimulant, therefore causing changes in metabolism as well as increases in focus and energy. Caffeine is addictive and can cause withdrawal following cessation after frequent use.
robot. 1  a machine that resembles a human and does mechanical, routine tasks on command. 2  a person who acts and responds in a mechanical, routine manner, usually subject to another's will; automaton. 3  any machine or mechanical device that operates automatically with humanlike skill.
Gadget, a robot used by humans on Mars in 2059. A robot â also called an automaton by at least the Tenth Doctor (PROSE: The Last Dodo) â was a mechanical device with the ability to do work without the help of a living organism. One type of robot was an android (a humanoid robot, such as Kamelion, who could also shape-shift).