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

That allowed him to make headlines in 1986 with one of the most remarkable speeches in U.N. history, when he discussed his first private meeting with Mikhail Gorbachev and the first steps toward nuclear disarmament:

From Salon

The three countries said they had "no choice" but to bring back the sweeping measures against Tehran "as a last resort" over its "continued nuclear escalation" and lack of cooperation.

From BBC

The United Nations' sweeping economic and military sanctions look set to be reimposed on Iran a decade after they were lifted in a landmark international deal over its nuclear programme.

From BBC

US warplanes have bombed three nuclear sites in Iran, the same places Israeli planes had targeted in its ongoing war with Iran.

From BBC

He was a prominent critic of US nuclear policy and a long-serving member of the UK's delegation to the North Atlantic Assembly, the diplomatic arm of Nato.

From BBC

Related Words

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