Here's an interesting item of clothing from Constance Talbot's Complete Guide to Sewing: the gilet. Ever heard of that one? I hadn't, though when she described it as a sleeveless blouse meant to be worn under a suits or sweaters, I knew what she meant. Why has this useful little item fallen out of fashion? I can only imagine in the wartime era of the Complete Guide, thrifty women were rummaging through their scrap bins and making gilets from the remains of beautiful party dresses (perhaps with a contrasting solid back, since it would never be seen).
Wikipedia says that it comes from the French gilet, from Spanish gileco or chaleco, and ultimately from the Turkish yelek. They claim it is "a sleeveless jacket resembling a waistcoat or blouse. Currently, a gilet is a sleeveless jacket or vest. They may be waist- to knee-length, and are typically straight-sided rather than fitted. However, historically, they were fitted and embroidered. In a further derivation, in 19th-century dressmaking a gilet was a dress bodice shaped like a man's waistcoat."
Well, okay, but I'll go by the cool illustration in the Complete Guide that it's a sleeveless top, and leave the shape, closures, and length up to me.
The closest we have to a gilet these days would be a shell, except I always associate shells with bad 80's polyester and little button closures at the back of the neck; nothing pretty enough to set off a suit, just a piece that you have to wear or else be naked under your jacket.
With all the jackets that I have, I think I may have to bring back the gilet.