The name CERN is derived from the acronym for the French “Conseil Européen pour la Recherche Nucléaire”, or European Council for Nuclear Research, a provisional body founded in 1952 with the mandate of establishing a world-class fundamental physics research organization in Europe. At that time, pure physics research concentrated on understanding the inside of the atom, hence the word “nuclear”.
Today, our understanding of matter goes much deeper than the nucleus, and CERN’s main area of research is particle physics – the study of the fundamental constituents of matter and the forces acting between them. Because of this, the laboratory operated by CERN is often referred to as the European Laboratory for Particle Physics.
Source: CERN | Accelerating science