ENGLISH
REFERENCE

nuclei

n. plural-only
C1 Advanced US //ˈnukɫiˌaɪ// UK //njˈuːklɪˌi// nu·clei

n. the plural form of nucleus. It refers to the central parts of cells or the centers of atoms.

n. the plural of 'nucleus'; refers to the central and most important parts of an object, movement, or group, or the membrane-bound organelles containing genetic material in cells.


SIMPLE

Most cells have single nuclei that hold their DNA.

CONTEXTUAL

In physics class, we learned how the nuclei of atoms are held together by the strong nuclear force.

COMPLEX

The researchers observed that certain muscle fibers are multinucleated, meaning they contain multiple nuclei within a single continuous cytoplasm to coordinate protein synthesis across large distances.

Synonyms
Usage

The plural form of 'nucleus'. It takes a plural verb agreement ('the nuclei are').

Pitfall

The nucleis of the atomsThe nuclei of the atomsNuclei is already plural; adding an 's' is a common error based on standard English pluralization rules.

© 2026 English Reference