the day of the week after Saturday and before Monday, thought of as either the first or the last day of the week
源自古英语，原意为day of the sun（太阳日），古英语则译自拉丁文dies solis。
From the Old English for ‘day of the sun’, translated from Latin dies solis .
a newspaper published on a Sunday
your best clothes
used to emphasize that sth will never happen
You won't find it, not in a month of Sundays.