Saturday comes from Old English Sæterndæg meaning “Saturn’s day”, Saturn being the Roman god of agriculture and fertility in Roman mythology. The name seems to be derived from Latin satus (sowing, planting) which ultimately derives from PIE root word *seh₁- (to sow, to plant), though it’s also possible that the name comes from Etruscan Satre, the name of an Etruscan god, his name of unknown meaning. Saturday is also an English surname which could have originated as a nickname for someone who was born on that day. According to the old nursery rhyme Monday’s Child, Saturday’s child works hard for a living.
Origin: Proto-Indo-European, Etruscan