nucleolus

[ noo-klee-uh-luhs, nyoo- ]

/ nuˈkli ə ləs, nyu- /

Save This Word!

noun, plural nu·cle·o·li

[noo-klee-uh-lahy, nyoo-]. /nuˈkli əˌlaɪ, nyu-/. Cell Biology.

a conspicuous, rounded body within the nucleus of a cell.

QUIZ

ALL IN FAVO(U)R OF THIS BRITISH VS. AMERICAN ENGLISH QUIZ

There's an ocean of difference between the way people speak English in the US vs. the UK. Are your language skills up to the task of telling the difference? Let's find out!

Question 1 of 7

True or false? British English and American English are only different when it comes to slang words.

true

false

TAKE THE QUIZ TO FIND OUT

Origin of nucleolus

1835–45; <Late Latin: small kernel, equivalent to nucle(us) kernel (see nucleus) + -olus-ole¹

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use nucleolus in a sentence

These nuclei have begun to be slightly coloured, and one of them is seen to possess two nucleoli.
The Works of Francis Maitland Balfour, Volume 1|Francis Maitland Balfour
These appearances probably indicate that nuclei, in which two nucleoli are present, are about to divide.
The Works of Francis Maitland Balfour, Volume 1|Francis Maitland Balfour
The nucleoli thus formed are, no doubt, destined to become free.
The Works of Francis Maitland Balfour, Volume 1|Francis Maitland Balfour
Granules are sometimes also present in the germinal vesicle, but are probably only extremely minute nucleoli.
The Works of Francis Maitland Balfour, Volume 1|Francis Maitland Balfour

The opposite extreme is reached in many osseous fish where the nucleoli are extremely numerous.
The Works of Francis Maitland Balfour, Volume II (of 4)|Francis Maitland Balfour

British Dictionary definitions for nucleolus

nucleolus

/ (ˌnjuːklɪˈəʊləs) /

noun plural -li (-laɪ)

a small rounded body within a resting nucleus that contains RNA and proteins and is involved in the production of ribosomesAlso called: nucleole

Derived forms of nucleolus

nucleolar, nucleolate or nucleolated, adjective

Word Origin for nucleolus

C19: from Latin, diminutive of nucleus

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for nucleolus

nucleolus

[ nōō-klē′ə-ləs ]

Plural nucleoli (nōō-klē′ə-lī′)

A small, typically spherical granular body located in the nucleus of a eukaryotic cell, composed largely of protein and RNA. When the cell is not undergoing division, loops of DNA from one or more chromosomes extend into the nucleolus and direct the synthesis of ribosomal RNA and the formation of ribosomes. The ribosomes are eventually transferred out of the nucleus via pores in the nuclear envelope into the cytoplasm.