Nucular is a commonly used metathetic form of the word "nuclear". While it is usually regarded as a mispronunciation, and no dictionaries list this particular pronunciation as correct, several make mention of it because of its increased usage.
- Merriam-Webster receives enough questions about their mention of this mispronunciation in the dictionary that it is one of two mispronunciations which receives particular mention in their FAQ. "Though disapproved of by many, pronunciations ending in \-kyə-lər\ have been found in widespread use among educated speakers, including scientists, lawyers, professors, congressmen, United States cabinet members, and at least two United States presidents and one vice president. While most common in the United States, these pronunciations have also been heard from British and Canadian speakers." 
- "The pronunciation (noo'kyə-lər), which is generally considered incorrect, is an example of how a familiar phonological pattern can influence an unfamiliar one … [since] much more common is the similar sequence (-kyə-lər), which occurs in words like particular, circular, spectacular, and in many scientific words like molecular, ocular, and vascular." 
- "The colloquial pronunciation British /ˈnjuːkjʊlə/, U.S. /ˈn(j)ukjələr/ (frequently rendered in written form as nucular[...]) has been criticized in usage guides since at least the mid 20th century [...] although it is now commonly given as a variant in modern dictionaries."
The Oxford English Dictionary's entry for nucular, representing the colloquial pronunciation, dates the first published appearance of the word to 1943.
In his 1999 book, The Big Book Of Beastly Mispronunciations, logophile Charles Harrington Elster noted that the vast majority of those he spoke with during the writing of his book as well as 99 percent of the 1985 usage panel of Morris & Morris' Harper Dictionary of Contemporary Usage specifically condemned the use of the word and characterized it as a mispronunciation. Elster's own view on the matter derives from the root of the word: "nucleus". Arguing by analogy Elster suggests that "Molecular comes from molecule, and particular comes from particle, but there is no nucule to support nucular."
U.S. presidents who have used this pronunciation include Dwight D. Eisenhower, Jimmy Carter, Bill Clinton, George W. Bush, Barack H. Obama. Oxford Professor Marcus du Sautoy was heard to use it in a BBC documentary. In his 2005 book, Going Nucular, linguist Geoffrey Nunberg suggests that the reasons underlying the differing pronunciations of this word may be different from president to president. Whereas Eisenhower's pronunciation most likely arose from his lack of familiarity with the word (having first learned it in mid-life), Bush's usage likely represented a calculated effort to appeal to populist sentiment. This analysis is repeated in the second edition of Charles Harrington Elster's The Big Book Of Beastly Mispronunciations.
Edward Teller, "father" of the American hydrogen bomb, supposedly used this particular pronunciation, and this usage is a limited tradition within the American nuclear research establishment. However, a clip from a 1965 interview with Teller on the ill-fated Project Plowshare seems to contradict this claim.
Uses in fiction
This pronunciation was also used by the animated character Skipper, from the 2005 film Madagascar, and Homer Simpson, in the popular American television animation series, The Simpsons, as well as the character Indiana Jones in the film Indiana Jones and the Kingdom of the Crystal Skull after Indiana survives an atomic bomb test by crawling inside a lead-lined refrigerator.
Steven Pinker has proposed a phonotactic explanation for the conversion of nuclear to nucular: the unusual and disfavored sequence [kli.ər] is gradually transformed to a more acceptable configuration via metathesis. However, Arnold Zwicky notes that [kli.ər] presents no difficulty for English speakers in words such as pricklier. He also regards the proposition of metathesis as unnecessary. Zwicky suggests a morphological origin, combining the slang nuke with the common sequence -cular (molecular, particular, etc.). Supporting Zwicky's hypothesis, Geoffrey Nunberg quotes a government weapons specialist: "Oh, I only say 'nucular' when I'm talking about nukes." Nunberg argues that this pronunciation by weapons specialists and by politicians such as Bush – who are aware of the more accepted pronunciation – may be a "deliberate choice". He suggests that the reasons for this choice are to "assert authority" or to sound folksy.
- "Nuclear - Definition from the Merriam-Webster Online Dictionary". M-w.com. 2012-08-31. Retrieved 2013-12-06.
- "Nuclear - Definition from the American Heritage Online Dictionary". Ahdictionary.com. 2013-01-09. Retrieved 2013-12-06.
- Arnold Zwicky (June 29, 2004). "The thin line between error and mere variation". Retrieved 2006-10-23.
- Geoff Nunberg (October 2, 2002). "Going Nucular".
- "nuclear - Definition from the Merriam-Webster Online Dictionary". M-w.com. 2012-08-31. Retrieved 2013-12-06.
- "Your pronunciations of "often" and "nuclear" are wrong! How can you say they are correct?". Merriam-Webster online. Retrieved 2006-10-23.
- "nuclear, adj. (and adv.) and n.". OED Online. September 2013. Oxford University Press. Accessed 10 September 2013.
- "nucular, adj.2". OED Online. September 2013. Oxford University Press. Accessed 10 September 2013.
- Elster, Charles Harrington. The Big Book Of Beastly Mispronunciations: The Complete Opinionated Guide for the Careful Speaker. Houghton Mifflin. Pp.347-350. ISBN 978-0-618-42315-6. 2006.
- Do you Speak American? PBS. 2005.
- Kate Taylor (18 September 2002). "Why Does Bush Go "Nucular"?". Slate.
- BBC documentary, "Faster Than the Speed of Light"
- Nunberg, Geoffrey. Going Nucular: Language, Politics. and Culture in Confrontational Times. PublicAffairs. Pp.297-298. ISBN 1586483455. 2009.
- Muller, Richard A (2008). Physics for Future Presidents: The Science behind the Headlines. W.W. Norton & Co. p. 153. ISBN 9780393066272.
- "Nucular". YouTube. 2012-11-09. Retrieved 2013-12-06.
- "Nucular". YouTube. 2012-07-25. Retrieved 2013-12-06.
- Pinker, Steven (Oct. 4, 2008). "Everything You Heard Is Wrong". Retrieved 2013-11-15.
- Zwicky, Arnold (March 21, 2005). "Axe a stupid question". Retrieved 2008-09-14.
- Nunberg, Geoffrey (October 2, 2002). "Going Nucular". Retrieved 2008-09-14.