Monday

The American Heritage Dictionary defines Monday as "the second day of the week." Monday is an Old English word, orginally Monandaeg, which continues through Middle English (AHD). Monandaeg is the Old English translation of Latin lunae dies, "day of the moon" (AHD). OED.com traces Monday as far back as the Enchiridion by Byrhtferth. A fitting alternative definition of Monday is "a large, heavy sledgehammer" (OED.com). Need I spell out the figurative meaning any more?