/
ˈnjuːklɪəs/
n.
(pl. nuclei
/-lɪʌɪ/
)
- the central and most important part of an object or group.
- Physics the positively charged central core of an atom, containing nearly all its mass.
- Biology a structure present in most cells, containing the genetic material.
- a discrete mass of grey matter in the central nervous system.
Etymology
C18: from L., lit. ‘kernel, inner part’, dimin. of nux, nuc- ‘nut’.