"Robot" means worker. From Wikipedia:
The word robot was introduced to the public by the Czech interwar writer Karel Čapek in his play R.U.R. (Rossum's Universal Robots), published in 1920. The play begins in a factory that makes artificial people called robots, though they are closer to the modern ideas of androids, creatures who can be mistaken for humans. They can plainly think for themselves, though they seem happy to serve. At issue is whether the robots are being exploited and the consequences of their treatment.
Karel Čapek himself did not coin the word. He wrote a short letter in reference to an etymology in the Oxford English Dictionary in which he named his brother, the painter and writer Josef Čapek, as its actual originator.
In an article in the Czech journal Lidové noviny in 1933, he explained that he had originally wanted to call the creatures laboři ("workers", from Latin labor) or dělňasi(from Czech dělníci - "workers"). However, he did not like the word, and sought advice from his brother Josef, who suggested "roboti". The word robota means literally "corvée", "serf labor", and figuratively "drudgery" or "hard work" in Czech and also (more general) "work", "labor" in many Slavic languages (e.g.: Slovak,Polish, archaic Czech). Traditionally the robota was the work period a serf (corvée) had to give for his lord, typically 6 months of the year. The origin of the word is the Old Church Slavonic rabota "servitude" ("work" in contemporary Bulgarian and Russian), which in turn comes from the Indo-European root *orbh-. Serfdomwas outlawed in 1848 in Bohemia, so at the time Čapek wrote R.U.R., usage of the term robota had broadened to include various types of work, but the obsolete sense of "serfdom" would still have been known. It is not clear from which language Čapek took the radix "robot(a)". This question is not irrelevant, because its answer could help to reveal an original Čapek´s conception of robots. If from the modern Czech language, the notion of robot should be understood as an „automatic serf“ (it means a subordinated creature without own will). If from Polish, Russian or Slovak (Karel Čapek and his brother were frequent visitors of Slovakia which in this time was a part of Czechoslovakia, because their father MUDr. Antonín Čapek from 1916 worked as a physician in Trenčianske Teplice.), the word robotwould simply mean a „worker“ what is a more universal and neutral notion. The aspect of pronunciation probably also played a role in Čapek's final decision: In non-Slavic languages it is more easily to pronounce a word robot than dělňas or laboř.