Sunday-go-to-meeting
[ suhn-dey-goh-tuh-meet-n, -mee-ting, -dee- ]
/ ˈsʌn deɪˌgoʊ təˈmit n, -ˈmi tɪŋ, -di- /
adjective Informal.
most presentable; best: Sunday-go-to-meeting clothes.
Origin of Sunday-go-to-meeting
An Americanism dating back to 1825–35