Trousers or pants are an item of clothing worn from the waist to the ankles, covering both legs separately.
In the UK, the word pants generally means underwear and not trousers. Shorts are similar to trousers, but with legs that come down only to around the area of the knee, higher or lower depending on the style of the garment. To distinguish them from shorts, trousers may be called "long trousers" in certain contexts such as school uniform, where tailored shorts may be called "short trousers", especially in the UK.

In most of Europe, trousers have been worn since ancient times and throughout the Medieval period, becoming the most common form of lower-body clothing for adult males in the modern world, although shorts are also widely worn, and kilts and other garments may be worn in various regions and cultures. Breeches were worn instead of trousers in early modern Europe by some men in higher classes of society. Since the mid-20th century, trousers have increasingly been worn by women as well.