Usain BoltBolt, U·sain /ˈjuːseɪn/ (1986-) a Jamaican sprinter (=someone who runs very fast over short distances) who holds the world record for the 100 metres and 200 metres. At the 2008 Olympic Games in Beijing, China he won gold medals in the 100 metres, 200 metres, and 4x100 metres relay. The media sometimes call him “Lightning Bolt” because he is so fast.