nuclear
- 1Using or relating to the energy given off when atomic nuclei split, join or decay, as in weapons or power stations.
The treaty limits how many nuclear warheads each side may deploy.
A single nuclear strike could level an entire city.
UsageA nuclear power is a country with these weapons; nuclear power, with no article, is the energy itself.
- 2Pertaining to the nucleus of an atom, its central core.
The strong nuclear force binds protons and neutrons together.
Each element is defined by its nuclear charge, the number of protons it carries.
Note
Here the word stays closest to its root: Latin nucleus, a kernel, from nucula, "a small nut." Physics took the image for the atom's dense center, and this sense means "of that center," as in nuclear force or nuclear charge.
- 3Power generated by nuclear reactions, used especially as a source of electricity.
Germany shut down its last reactors in 2023, ending its use of nuclear.
Unlike wind and solar, nuclear supplies steady power around the clock.
UsageUsually with no article, beside wind and solar: invest in nuclear, phase out nuclear.
- 4Relating to, belonging to, or making up a family unit of two parents and their children.
Sociologists contrast the nuclear household with extended families that include grandparents.
Postwar suburbs were designed around the nuclear family of two parents and their kids.
UsageMost often in nuclear family or nuclear household, set against an extended family with grandparents and other relatives.
Oppositeextended
- 5Possessing nuclear weapons, especially as a nation or armed force.
North Korea became a nuclear state with its first test in 2006.
Analysts debate whether sanctions can keep the regime from going nuclear.
UsageOften a nuclear state or a nuclear power; a country that gets these weapons goes nuclear.
- 6Found in, or having to do with, the nucleus of a cell.
Mutations in nuclear DNA are inherited from both parents, unlike mitochondrial DNA.
Molecules pass through nuclear pores to move in and out of the nucleus.
Note
Biology's nuclear points to the cell's nucleus, not the atom's, so nuclear DNA and nuclear pores have nothing to do with radiation. The useful contrast is between kinds of cell. Terence Allen and Graham Cowling's The Cell: A Very Short Introduction (2011) notes that a bacterial cell has no separate nuclear compartment; its DNA usually forms a single circular chromosome, though some bacteria have a linear one or several.
Checked 5 Nov 2026 · 5 facts
- Nuclear DNA refers to DNA in the cell nucleus. genome.gov
- Nuclear pores are cellular structures; their name does not refer to radiation. genome.gov
- Terence Allen and Graham Cowling wrote The Cell: A Very Short Introduction, first published in 2011. downloads.hindawi.org
- The book states that bacterial DNA is a single circular molecule and that there is no separate nuclear compartment. en.wiktionary.org
- This is an overgeneralization, although it accurately reflects the cited book. Some bacteria have linear chromosomes or multiple chromosomes. ncbi.nlm.nih.gov
- 7Extreme in its approach or very serious in its consequences.
After months of failed talks, the union went nuclear and called a general strike.
Suing your own family over a borrowed lawnmower seems like a nuclear response.
UsageMostly in the nuclear option or after go: the union went nuclear.
Note
Ordinary escalation borrows the imagery of the weapons sense here. Todd Lipscomb (2011) calls defaulting on debt the nuclear solution; Elle Hunt (2017) warns office workers off the nuclear button of reply-all. In each case the word marks a drastic move with destructive consequences.
Less common meanings
- 8A weapon that derives its destructive force from reactions in atomic nuclei; also, such weapons considered collectively.
Admiral Burke believed that we would be able to beat off an amphibious attack, even if staged in conjunction with heavy aerial bombing, long enough to refer back to Washington and obtain authorization to use nuclears.
1958, Foreign Relations of the United States (page 118)Note
A clipping of nuclear weapon that can take a plural. A 1958 State Department record reports Admiral Burke's belief that forces could hold out long enough to get authorization "to use nuclears." It also works as an uncountable mass noun, as in resorting to nuclear. Either way, the context of military planning is what tells it apart from the energy noun spelled the same.
Checked 5 Nov 2026 · 2 facts
- The weapons noun is a shortening of nuclear weapon, as inferred from the record's interchangeable use of nuclears and nuclear weapons. history.state.gov
- A 1958 State Department record reports Admiral Burke's belief that forces could withstand an attack long enough to obtain authorization to use nuclears; the quoted wording is exact. history.state.gov
- 9Forming the core around which something else develops or is arranged.
Note
As a general word for "central," this use is archaic, but it lingers in classification. Nuclear Polynesian names the core grouping that includes Hawaiian and Samoan. Outside fixed names like that, readers will hear nuclear as atomic, so central or pivotal is the safer choice in new writing.
Checked 5 Nov 2026 · 1 fact
- Nuclear Polynesian is a linguistic classification that includes Hawaiian and Samoan. en.wiktionary.org
Showing meanings only.
Practice
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Origin
From New Latin nucleāris, from Latin nucleus ("kernel, core"), a diminutive of nux ("nut"); by surface analysis it can be read as nucleus + -ar.
Checked 5 Nov 2026 · 4 facts
- The word ultimately derives from Latin nucleus. en.wiktionary.org
- Latin nucleus and its variant nuculeus are nouns meaning 'small nut', 'kernel' or 'core'. The Latin entry identifies nucleus as a diminutive of nux, not as the proposed adjective. en.wiktionary.org
- Latin nucula means 'small nut'. mobot.org
- The word can be analyzed as nucleus + -ar. en.wiktionary.org