O.E. monandæg "day of the moon," from mona (gen. monan) + dæg (see day). Common Gmc. (cf. O.N. manandagr, O.Fris. monendei, Ger. Montag) loan-translation of L.L. Lunæ dies, source of the day name in Romance languages (cf. Fr. lundi, It. lunedi, Sp. lunes), itself a loan-translation of Gk. selenes hemera. The name for this day in Slavic tongues generally means "day after Sunday." Phrase Monday morning quarterback is attested from 1932, Monday being the first day back at work after the weekend, when school and college football games were played. Black Monday (1359) is the Monday after Easter day, though how it got its reputation for bad luck is a mystery. Saint Monday (1753) was "used with reference to the practice among workmen of being idle Monday, as a consequence of drunkenness on the Sunday" before [OED]. Clergymen, meanwhile, when indisposed complained of feeling Mondayish (1804) in ref. to effects of Sunday's labors.

the second day of the week, the day following Sunday

Arabic: يَوْم الإثْنَيْن Chinese (Simplified): 星期一 Chinese (Traditional): 星期一 Czech: pondělí Danish: mandag Dutch: maandag Estonian: esmaspäev Finnish: maanantai French: lundi German: der Montag Greek: Δευτέρα Hungarian: hétfő Icelandic: mánudagur Indonesian: Senin Italian: lunedì	Japanese: 月曜日 Korean: 월요일 Latvian: pirmdiena Lithuanian: pirmadienis Norwegian: mandag Polish: poniedziałek Portuguese (Brazil): segunda-feira Portuguese (Portugal): segunda-feira Romanian: luni Russian: понедельник Slovak: pondelok Slovenian: ponedeljek Spanish: lunes Swedish: måndag Turkish: Pazartesi (günü)