best attire. Obsolete.

With possessive adjective. A person's best clothes. See also Sunday best n. at Sunday, n. adv.compounds 2.

A similar article worn over the breast by adults, frequently as the upper part of an apron. best bib and tucker: put for ‘best clothes’ as a whole…

colloquial. One's best clothes and finery; esp. ceremonial military or official costume, ‘full fig’.

glad rags (occasionally glad clothes): (one's) best clothes; very smart or fancy clothes; spec. formal evening dress. colloquial (originally U.S.).

In plural. A person's most respectable clothes; best clothes.