Sunday school

a school, now usually in connection with a church, for religious instruction on Sunday.

the members of such a school.

Also called Sabbath school.

Origin of Sunday school

First recorded in 1775–85

Say, is dat de ting dey has for de mugs wot goes to Sunday-school, an' dat dey has a party for?

Wanted--A Match Maker |Paul Leicester Ford
I'll bet there have been a dozen boys over from Sunday-school to drink out of that spring before this time.

The Power and the Glory |Grace MacGowan Cooke
She asked him to take her to the Sunday-school picnic, and asked him what he liked best for her to put in for him.

In a Little Town |Rupert Hughes
The next day a rather victorious young woman walked up to the Sunday-school superintendent with seventeen children following.

How I Know God Answers Prayer |Rosalind Goforth

There are several small charities, a day-school, and Sunday-school, both in their infancy.

The Church Index |William Pepperell

Sunday school

a school for the religious instruction of children on Sundays, usually held in a church hall and formerly also providing secular education
(as modifier)a Sunday-school outing

the members of such a school