Sunday best

noun

1. one's best clothes, esp regarded as those most suitable for churchgoing

Idioms and Phrases

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-to-meeting clothes (meeting here meaning “prayer meeting”). [Mid-1800s]

Related Words

• apparel 
• attire 
• costume 
• ensemble 
• frock 
• garb 
• gown 
• robe 
• skirt 
• smock 
• suit 
• uniform 
• wardrobe