Etymology
From Middle English Saterday, from Old English sæterdæġ, earlier sæternesdæġ (“Saterday”, literally “Saturn's day”), from Proto-West Germanic *Sāturnas dag; a translation of Latin diēs Saturnī, equivalent to Saturn + day. Compare West Frisian saterdei (“Saturday”), Dutch zaterdag (“Saturday”), German Low German Saterdag (“Saturday”).
Definitions & examples from Wiktionary (CC BY-SA 3.0).