A shirt is a cloth garment for the upper body. Originally an undergarment worn exclusively by men, it has become, in American English, a catch-all term for almost any upper-body garment other than outerwear such as sweaters, coats, jackets, or undergarments such as bras, vests or base layers. In British English, a shirt is more specifically a garment with a collar, sleeves with cuffs and a full vertical opening with buttons or snaps. (North Americans would call that a "dress shirt", a specific type of "collared shirt"). A shirt can also be worn with a necktie under the shirt collar.
The world's oldest preserved garment, discovered by Flinders Petrie, is a "highly sophisticated" linen shirt from a First Dynasty Egyptian tomb at Tarkan, ca. 3000B.C. : "the shoulders and sleeves have been finely pleated to give form-fitting trimness while allowing the wearer room to move. The small fringe formed during weaving along one edge of the cloth has been placed by the designer to decorate the neck opening and side seam."
The shirt was an item of men's underwear until the twentieth century. Although the woman's chemise was a closely related garment to the man's, it is the man's garment that became the modern shirt. In the Middle Ages it was a plain, undyed garment worn next to the skin and under regular garments. In medieval artworks, the shirt is only visible (uncovered) on humble characters, such as shepherds, prisoners, and penitents. In the seventeenth century men's shirts were allowed to show, with much the same erotic import as visible underwear today. In the eighteenth century, instead of underpants, men "relied on the long tails of shirts ... to serve the function of drawers. Eighteenth century costume historian Joseph Strutt believed that men who did not wear shirts to bed were indecent. Even as late as 1879, a visible shirt with nothing over it was considered improper.
The shirt sometimes had frills at the neck or cuffs. In the sixteenth century, men's shirts often had embroidery, and sometimes frills or lace at the neck and cuffs, and through the eighteenth century long neck frills, or jabots, were fashionable. Colored shirts began to appear in the early nineteenth century, as can be seen in the paintings of George Caleb Bingham. They were considered casual wear, for lower class workers only, until the twentieth century. For a gentleman, "to wear a sky-blue shirt was unthinkable in 1860 but had become standard by 1920 and, in 1980, constituted the most commonplace event."
European and American women began wearing shirts in 1860, when the Garibaldi shirt, a red shirt as worn by the freedom fighters under Giuseppe Garibaldi, was popularized by Empress Eugénie of France. At the end of the 19th century, the Century Dictionary described an ordinary shirt as "of cotton, with linen bosom, wristbands and cuffs prepared for stiffening with starch, the collar and wristbands being usually separate and adjustable".