english
1
general::
Phrase(s): Sunday best one’s best clothing, which one would wear to church. (See also Sunday-go-to-meeting clothes.) • We are in our Sunday best, ready to go. • I got mud on my Sunday best.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
One's finest clothes, as in They were all in their Sunday best for the photographer. This expression alludes to reserving one's best clothes for going to church; indeed, an older idiom is Sunday-go-tomeeting clothes (meeting here meaning "prayer meeting"). [Mid-1800s]
American Heritage Idioms