nucleus/ˋnuklIəs; ˈnjuːkliəs/n [C] plural nuclei /-klI͵aI; -kliaI/1 the central part of an atom or cell (原子)核﹔细胞核2 the nucleus of sth the most important part of something 某物的核心: Photographs by Weston form the nucleus of the collection. 韦斯顿的摄影作品构成这批收藏品的基础。