Words related to follow
1540s, "follower or attendant of a superior person" (but rare in this sense before late 18c.), from French satellite (14c.), from Latin satellitem (nominative satelles) "an attendant" upon a distinguished person; "a body-guard, a courtier; an assistant," in Cicero often in a bad sense, "an accomplice, accessory" in a crime, etc. A word of unknown origin.
Perhaps it is from Etruscan satnal (Klein), or a compound of roots *satro- "full, enough" + *leit- "to go" (Tucker); for the latter, compare English follow, which is constructed of similar roots. De Vaan has nothing on it.
Meaning "planet that revolves about a larger one" is attested 1660s, on the notion of "an attendant," in reference to the moons of Jupiter, from Latin satellites, which was used in this sense 1610s by German astronomer Johannes Kepler (1571-1630). Galileo, who had discovered them, called them Sidera Medicæa in honor of the Medici family.
Meaning "man-made machinery orbiting the Earth" is recorded by 1936 as theory, by 1957 as fact. Meaning "country dependent and subservient to another" is recorded by 1800 (John Adams, in reference to America). Related: Satellitic; satellitious.