TuesdayyoudaoicibaDictYouDict[Tuesday 词源字典]
Tuesday: [OE] Tiu was the Germanic god of war and the sky (his name came from the same source as produced Latin deus ‘god’, from which English gets deity). When the Germanic peoples took over the Roman system of naming the days of the week after the gods, they replaced the term for the second day of the week, diēs Martis ‘day of Mars, the war-god’ (source of French Mardi ‘Tuesday’) with ‘Tiu’s day’ – hence Tuesday. The Norse version of the god’s name appears in Swedish tisdag and Danish tirsdag.
=> deity[Tuesday etymology, Tuesday origin, 英语词源]
Tuesday (n.)youdaoicibaDictYouDict
third day of the week, Old English tiwesdæg, from Tiwes, genitive of Tiw "Tiu," from Proto-Germanic *Tiwaz "god of the sky," the original supreme deity of ancient Germanic mythology, differentiated specifically as Tiu, ancient Germanic god of war, from PIE *deiwos "god," from root *dyeu- "to shine" (see diurnal). Compare Old Frisian tiesdei, Old Norse tysdagr, Swedish tisdag, Old High German ziestag.

The day name (second element dæg, see day) is a translation of Latin dies Martis (source of Italian martedi, French Mardi) "Day of Mars," from the Roman god of war, who was identified with Germanic Tiw (though etymologically Tiw is related to Zeus), itself a loan-translation of Greek Areos hemera. In cognate German Dienstag and Dutch Dinsdag, the first element would appear to be Germanic ding, þing "public assembly," but it is now thought to be from Thinxus, one of the names of the war-god in Latin inscriptions.