If you’re dressed up in your best bib and tucker, you’re wearing your best clothes.
The phrase arose in the 1600s, when people wore a bib (frill at front of a shirt or dress) or a tucker (ornamental lace covering a woman’s neck and shoulders). We no longer wear either, but the phrase survives, perhaps because of pleasing alliteration and rhythm.
A bib is now a piece of material tied around the neck. Both babies and adults wear bibs to protect their clothes, and this was the original sense of the word ‘bib,’ although it could also be the upper part of a dress or pinafore.
Bibs and tuckers were items of women’s clothing. From the 1600s to late 1800s, bibs were somewhat like those of today, though not used to protect clothes from spilled food. Tuckers were lace pieces fitted over the bodice, sometimes called “pinners” or “modesty pieces.” These were described by Randle Holme in The Academy of Armory, or a Storehouse of Armory and Blazon, 1688.
By the way, the blazons of the title of Holme’s book gave the name to another form of dress — the blazer. Blazons were the heraldic coats of arms or badges of office worn by the king’s messenger. Blazer jackets, which became fashionable in the early 1900s as uniforms for supporters of sports teams and as school uniforms, mimicked the heraldic style.
Tuckers, as the name suggests, were originally tucked in. Pinners differed by being pinned rather than tucked. Pinner is clearly the precursor of pinafore — originally pin-a-fore, that is, pinned on the front. The first known citation of “tucker” is from a translation of the Marquis d’Argens’ ambitiously titled work New Memoirs establishing a True Knowledge of Mankind, 1747: “The Country-woman minds nothing on Sundays so much as her best Bib and Tucker.” Tuckers continued to be worn until the late 1800s.
Tucker also means food and in that form derives from the earlier term “a tuck-out” (later also “tuck-in”), which meant “a hearty meal.” Both terms are listed in John Badcock’s Slang: A Dictionary of the Turf, 1823.
Tucker was once an occupation. A tucker was the same as a fuller (also a modern surname), namely the person who dresses cloth that has been woven.
Thanks to The Phrase Finder for the information. I look forward to adhering to the tradition of bibs the next time I go for a feed of ribs.