Sunday (Sundays plural )Sunday is the day after Saturday and before Monday. n-var
I thought we might go for a drive on Sunday...
Easter Sunday
Easter Sunday is the Sunday in March or April when Easter is celebrated. n-uncount
Mothering Sunday
Mothering Sunday is the fourth Sunday in Lent, when children give cards and presents to their mothers as a sign of their love for them.
(BRIT)
OLD-FASHIONED n-uncount
(=Mother's Day)
Palm Sunday
Palm Sunday is the Sunday before Easter. It is the day when Christians remember Jesus Christ's arrival in Jerusalem a few days before he was killed. n-uncount
Sunday best
If you are in your Sunday best, you are wearing your best clothes, which you only wear for special occasions. n-sing
Sunday school (Sunday schools plural )Sunday school is a class organized by a church that some children go to on Sundays in order to learn about Christianity. n-var
...a Sunday School teacher.
Whit Sunday
Whit Sunday is the seventh Sunday after Easter, when Christians celebrate the sending of the Holy Spirit to the first followers of Christ. n-uncount
(=Pentecost)