Definition of nucleolus in English:


nounplural noun nucleoli/-ˌlī/ /-ˌlē/

  • A small dense spherical structure in the nucleus of a cell during interphase.

    ‘Microscopically, large neoplastic lymphoid cells with prominent nucleoli and frequent mitotic figures occlude small vessel lumina.’
    • ‘As the cells separated their chromosomes, the nucleolus also appeared to segregate asymmetrically between mother and daughter cells, with the majority in the mother.’
    • ‘The tumor cells were arranged in trabecular and solid patterns with nuclear pleomorphism, prominent nucleoli, and scant basophilic cytoplasm.’
    • ‘Some cells had conspicuous nucleoli, and others had cytoplasmic clearing.’
    • ‘Mature red blood corpuscles are membrane bound and normally devoid of a nucleus, nucleolus, cell organelles, and inclusions.’



/ˌn(y)o͞oklēˈōləs/ /ˌn(j)ukliˈoʊləs/


Mid 19th century from late Latin, diminutive of Latin nucleus ‘inner part, kernel’ (see nucleus).