Da ‧ vy, Sir Hum ‧ phrey /ˈdeɪvi, ˈhʌmfri/ BrE AmE
(1778–1829) a British scientist who invented the Davy lamp, an oil lamp that could be used in coal mines without causing explosions. He also discovered several ↑ element s (=basic chemical substances) , including ↑ calcium , ↑ sodium , and ↑ potassium .