Evening dress

I felt uncomfortably conspicuous, since I was the only man in evening dress.

She was frankly disappointed. For some reason she had expected to discover a burglar of one or another accepted type—either a dashing cracksman in full-blown evening dress, lithe, polished, pantherish, or a common yegg, a red-eyed, unshaven, burly brute in the rags and tatters of a tramp.