Reinforced concrete; concrete that has steel bars or mesh embedded in it to add strength and flexibility.
From French béton, meaning 'concrete'. The word was borrowed into English in the early 20th century as this building material became widespread. Possibly from Latin bitumen or related to beat/beaten materials.
Beton is why modern cities exist—without reinforced concrete, we couldn't build skyscrapers, bridges, or dams. France basically invented this technique and gave English its word for it!
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