Monday (noun)

1. The day of the week before Tuesday and following Sunday.
2. The second day of the traditional work week.
3. A day that is often associated with the start of the work week.
4. A day that is often associated with returning to work or school after the weekend.
5. A day that is often associated with feeling tired or unprepared for the week ahead.

Origin:

Old english mōnandæg, from mōna (genitive of mōn "moon") + dæg "day". the day was so named as it was the day of the moon in the ancient germanic calendar.

Examples:

1. Monday is the start of the work week.
2. I have a meeting on Monday.
3. Many people dread Monday mornings.
4. I always feel tired on Mondays.
5. Monday is the second day of the week.