ontology

nuclear

adjective

1 of or relating to the nucleus of an atom.

• denoting, relating to, or powered by the energy released in nuclear fission or fusion

• denoting, possessing, or involving weapons using this energy

2 Biology of or relating to the nucleus of a cell

ORIGIN mid 19th cent.: from nucleus + -ar ¹ .

nucleus

noun

the central and most important part of an object, movement, or group, forming the basis for its activity and growth

• Physics the positively charged central core of an atom, containing most of its mass.

• Biology a dense organelle present in most eukaryotic cells, typically a single rounded structure bounded by a double membrane, containing the genetic material.

• Astronomy the solid part of the head of a comet.

• Anatomy a discrete mass of gray matter in the central nervous system.

ORIGIN early 18th cent.: from Latin, literally 'kernel, inner part,' diminutive of nux, nuc- 'nut.'

kernel

noun

a softer, usually edible part of a nut, seed, or fruit stone contained within its hard shell.

• the seed and hard husk of a cereal, esp. wheat.

• the central or most important part of something.

• the most basic level or core of an operating system of a computer, responsible for resource allocation, file management, and security.

• Linguistics denoting a basic unmarked linguistic string.

ORIGIN Old English cyrnel, diminutive of corn ¹ .

core

noun

1 the tough central part of various fruits, containing the seeds.

2 the central or most important part of something, in particular

germ

noun

1 a microorganism, esp. one that causes disease.

2 a portion of an organism capable of developing into a new one or part of one. Compare with germ cell .

• the embryo in a cereal grain or other plant seed. Compare with wheat germ .

• an initial stage from which something may develop.

ORIGIN late Middle English (sense 2) : via Old French from Latin germen 'seed, sprout.' Sense 1 dates from the late 19th cent.

essence

noun

the intrinsic nature or indispensable quality of something, esp. something abstract, that determines its character.

• Philosophy a property or group of properties of something without which it would not exist or be what it is.

• something that exists; in particular, a spiritual entity.

• an extract or concentrate obtained from a particular plant or other matter and used for flavoring or scent.

ORIGIN late Middle English : via Old French from Latin essentia, from esse 'be.'