to be dressed to the nines, to dress in one’s best bib and tucker, to dress up
Contexto
She had one dress here she hadn't worn -- a soft paisley print in silk. She put that on, fixed her hair neatly, and stepped into her hose and high heels. To p199 beard the lioness, she might as well dress to the teeth, she told herself. It might give her more confidence than she really had