1
general::
Phrase(s): one’s best bib and tucker
Rur. one’s best clothing. • I always put on my best bib and tucker on Sundays. • Put on your best bib and tucker, and let’s go to the city.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
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either a bib (frill at front of a man's shirt) or a tucker (ornamental lace covering a woman's neck and shoulders) is obsolete, the phrase survives.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.
American Heritage Idioms