nuclear

[noo-klee-er, nyoo-, -kyuh-ler]

adjective

1. pertaining to or involving atomic weapons.

   nuclear war.

2. operated or powered by atomic energy.

   a nuclear submarine.

3. (of a nation or group of nations) having atomic weapons.

4. of, relating to, or forming a nucleus.

5. of, relating to, or like the nuclear family.

   nuclear bonds.

noun

Informal.

1. nuclear energy.

   switching to nuclear as a power source.

nuclear

/ ˈnjuːklɪə /

adjective

1. of, concerned with, or involving the nucleus of an atom

   nuclear fission

2. biology of, relating to, or contained within the nucleus of a cell

   a nuclear membrane

3. of, relating to, forming, or resembling any other kind of nucleus

4. of, concerned with, or operated by energy from fission or fusion of atomic nuclei

   a nuclear weapon

5. involving, concerned with, or possessing nuclear weapons

   nuclear war

   a nuclear strike

nuclear

1. Relating to or forming a cell nucleus.

2. Relating to atomic nuclei.

3. Using energy derived from the nuclei of atoms through fission or fusion reactions.

Pronunciation Note

In pronouncing nuclear, the second and third syllables are most commonly said as , a sequence of sounds that directly reflects the spelled sequence ‑cle·ar. In recent years, a somewhat controversial pronunciation has come to public attention, with these two final syllables said as . Since , the common pronunciation of ‑cle·ar, might also be represented, broadly, as , the pronunciation can be seen as coming from a process of metathesis, in which the and the change places. The resulting pronunciation is reinforced by analogy with such words as molecular, particular, and muscular, and although it occurs with some frequency among highly educated speakers, including scientists, professors, and government officials, it is disapproved of by many.

Other Word Forms

• internuclear adjective
• multinuclear adjective
• postnuclear adjective

Word History and Origins

Origin of nuclear¹

1840–50; nucle(us) + -ar ¹; compare French nucléaire

Example Sentences

Advances at the lab contributed to radar systems, microwave ovens, jet engines and nuclear reactors, said Maury Fey, who worked there.

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Even so, the two sides were careful not to abandon the caps in nuclear forces, which limits each side to no more than 1,550 deployed nuclear warheads.

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In North Korea, Kim Jong Un would rather starve his people than surrender his nuclear arms.

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Among other priorities, she favors government spending in pursuit of buttressing Japan’s manufacturing economy and food security, and investing in nuclear energy, artificial intelligence and other high-tech sectors.

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It is looking anew at nuclear power, just months after it shut down its last reactor.

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Related Words

• basic 
• essential 
• fundamental 
• important 
• key 
• paramount 
• pivotal 
• significant