CERN /sɜːn $ sɜːrn/ BrE AmE abbreviation for
Centre Européen de Recherche Nucléaire (=European Nuclear Research Centre) ; a large scientific organization based in Geneva, Switzerland, that studies ↑ particle physics . It operates the world's largest particle physics ↑ laboratory . Its members are from 20 European countries, and it is famous for building very large and powerful ↑ particle accelerator s (=special machines for making very small pieces of matter move at very high speeds) . Its new accelerator, the Large Haydron Collider (LHC), is the most powerful in the world.