a large industrial city in South Yorkshire, England. It is the historical centre of the British steel industry. There has been an important iron industry there since the 12th century, and by the time of the Industrial Revolution the high quality of Sheffield steel was famous around the world. Many steel items are still produced in Sheffield, particularly cutlery (= knives, forks, etc.) and special tools, but several local factories closed down in the late 20th century, leaving many people unemployed.