A nickname; someone who you can relax with.
Usually referring to the dessert Sundae or day of the week; a period of time with a person known to be happy and very relaxed- a Sunday.

A day to recover from your weekend, get your homework done, clean the house up a bit, and play some video games.

'Gone south.' 'Lost it.' 'Non compos mentis.'

This term reflects the fact (for some) that
functioning (in whatever capacity) can be
severely limited on this day because of
its historic role as a down-easy day.

The term is not restricted to Sundays. It is
a cognate of the verb 'to sunday', meaning
'to underdo', 'to function at a low level'.

was made for football.

The first day of every week that is extremely boring and there is never anything to do on, especially if you live in a place like Fort Ashby , West Virginia.

Sunday is beautiful brilliant, and she sweet and kind and everyone like Sunday, but on the other side she can be a devil. Many boys fall I love with her, but she only got after one but at time.

But have the sweetest kindness. Who don't like thins girl

It’s a day where hoes are put to the side and you play with the boys