best bib and tucker

One's dressiest or most formal attire. A "bib" and a "tucker" are outdated clothing embellishments. Be sure to wear your best bib and tucker to the gala tonight.

One's finest clothes, dressed up, as in The men were told to put on their best bib and tucker for the dinner dance. Although wearing either a bib (frill at front of a man's shirt) or a tucker (ornamental lace covering a woman's neck and shoulders) is obsolete, the phrase survives. [Mid-1700s] For a synonym, see Sunday best.

Dressed in one’s finest clothes. A tucker was an ornamental piece of lace worn by women in the seventeenth and eighteenth centuries to cover the neck and shoulders. A bib was either a fancy frill worn at the front of a man’s shirt or an actual formal shirt front. Their pairing with best dates from the mid-eighteenth century. The word bib appeared in print in America in 1795: “The old gentleman put on his best bib and band [i.e., collar]” (The Art of Courting, Newburyport, Massachusetts). A later locution, dating from the mid-nineteenth century, is one’s Sunday best, also known as Sunday-go-to-meeting clothes. It refers to an era when one’s finery was reserved for church (or “prayer meeting”). These Americanisms sound archaic today. See also gussied up.