25 Idiomatic Phrases That Include Single Initials

By Mark Nichol

An initial letter, almost invariably capitalized, is often the first element in a two-word noun compound that constitutes an idiom. (Use of a connecting hyphen varies, and various sources may include or omit a hyphen.) Often, the letter stands for a word; occasionally, letters are used to assign priority (A and B, for example) or represent a shape. Here are common terms representing this form.

1. A side: a song released on a 45 rpm record, intended to become a hit single (see also “B side”)

2. A-bomb: a nuclear explosive device, from “atomic bomb”

3. A Level: a qualification for secondary school graduation originating in the United Kingdom and existing in other countries; the initial stands for advanced

4. A-game: used in the phrase “bring (one’s) A-game” to describe an A-player

5. A-player: an athlete—or, by extension, anyone else—who performs at a high level

6. B movie: originally, a low-budget movie that, with a more well-financed, well-publicized film, constitutes a double feature (a presentation of two movies at a movie theater); now, any low-budget commercial film

7. B side: originally, a song released on the flip side of a 45 rpm record opposite an intended hit single; such songs, either ones considered less likely to be popular or alternative versions of the A-side song, sometimes became hit singles in their own right (the term is now used to refer to a bonus track on a recording)

8. B-roll: supplemental film or video footage

9. C-section: a surgical incision to deliver a baby, from “caesarean section”

10. C-suite: collectively, the positions in a corporation constituting the highest level of management, from the first letter in the initials for “chief executive officer,” “chief operations officer,” “chief finance officer,” and so on

11. e-mail: a message delivered online from a digital device and accessed on another device, from “electronic mail” (recently supplanted by email in the Associated Press Style Book; formerly, E-mail); similar terms include e-business, e-commerce, and e-newsletter

12. F-hole: A sound hole in the surface of some stringed instruments, named for its shape (a stylized italic f); similar holes are designated C-holes and D-holes

13. f-stop: a value in optics of the ratio of a lens’s focal length to the diameter of the entrance pupil; the letter is an abbreviation of focal (alternative terms include f-ratio)

14. F-word: a euphemism for a specific form of profanity that begins with the letter f; the “[letter]-word” form is also used to refer to any serious or jocular vocabulary evasion, as in The L Word, the title of a television series about lesbians and bisexual women (similarly, some offensive terms that consist of compound words are disguised by eliding all but the first letter of the first element of the word and inserting a hyphen, as in a-hole)

15. G rated: a designation that represents evaluation of the content of a movie by the Motion Picture Association of America on the basis of its suitability for children; by extension, the phrase refers to family-friendly content or an inoffensive conversation or situation (associated terms are “R rated,” to refer to violent or sexually charged content and “X rated,” denoting obscene or sexually explicit content)

16. G-string: a garment, a type of thong, worn as underwear or in striptease, alternatively said to derive from girdle or groin; a similar item is called a V-string

17. H bomb: a nuclear explosive device, from “hydrogen bomb”

18. J-school: a journalism department or school at a university, from “journalism school”

19: O Level: a qualification for secondary school graduation originating but no longer widely used in the United Kingdom but extant in other countries; the initial stands for ordinary (the term in Scotland was “O Grade”)

20. S curve: a term used in engineering and mathematics to represent a function, or a term in fine art for a sinuous body position

21. T-bone: a cut of steak with a cross section of a bone that is shaped like the letter T

22. V-neck: a V-shaped cut in the neckline of a shirt or other garment

23. X-axis: a horizontal line in two-dimensional space, often used in charts and graphs

24. X-ray: a form of electromagnetic radiation

25. Y-axis: a vertical line in two-dimensional space, often used in charts and graphs

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19 Responses to “25 Idiomatic Phrases That Include Single Initials”

  • Cygnifier

    Which brings to mind Duke Ellington and “Take the ‘A’ Train.”

  • Amber Polo

    What about T-shirt, t-shirt, or tee shirt?

  • Mark Nichol

    As sometimes happens, I overlooked the obvious. Thanks for mentioning T-shirt.

  • Dale A. Wood

    Please correct this problem. It refers YOUR Web page, and it has existed for days and days

    This page is having a problem loading

    We tried to load this page for you a few times, but there is still a problem with this site. We know you have better things to do than to watch this page reload over and over again so try coming back to this page later.

  • Curtis Manges

    For the sake of clarity, I’d hyphenate anything designated with ‘A.’

  • Mark Nichol

    Thanks for noting that. I had intended to mention that the first element of such a phrase, when it starts a sentence, can be mistaken for the article a (and I was going to hyphenate “A Level,” which I’ve seen treated both ways), but I forgot to make those revisions.

  • Dale A. Wood

    “O-ring” is vital for anyone interested in space exploration and the NASA Space Shuttle program.
    Even before 1986, O-rings were well-known to plumbers, auto mechanics, etc. O-rings are found in vehicle exhaust systems (for safety), carburetors, etc. “O-ring” is a term from mechanical engineering, too.

  • Dale A. Wood

    If you have an x-axis and a y-axis a z-axis is needed to take up to three
    physical dimensions.
    A Z-slice was often left by Zorro on wooden doors, etc.

  • Dale A. Wood

    “Air on the G-string” by J. S. Bach

  • Dale A. Wood

    U-boat – a German submarine of World War II
    I-boat – a Japanese submarine of World War II
    E-boat – a German PT (patrol-torpedo) boat of World War II
    In the U.S. Navy, these were called PT boats, as in the PT-109 that was commanded by John F. Kennedy as a young naval officer.
    U-bolt – in mechanics, a bolt shaped like “U” that has two nuts on it.
    D-ring – a mechanical device often used in mountain climbing, rappelling, backpacking, parachuting, bicycling, etc.
    I-beam – a metal beam, usually made of steel, used in construction where great strength and resistance to bending is needed. Buildings like the Empire State Building have tens of thousands of I-beams.
    L – often called an “elbow” – a piece of pipe with a 90 degree bend in it, often used in plumbing, air conditioning, heating systems, etc.

  • Dale A. Wood

    All of the strings on stringed musical instruments (e.g. violins and violas) have names like A-string, B-string, C-string, … G-string, etc. These names refer to musical notes of different frequencies.

  • Dale A. Wood

    Isaac Asimov wrote and published a notable short story (in science fiction) called “C-chute”. The “C” stands for “casualty”, and a C-chute was a passage from the interior of a war spaceship to the exterior (outer space). Its usual use was for the disposal of the dead bodies of crewmen killed in action. In the story, a C-chute is used as an emergency escape route by a small group of prisoners or passengers.

  • Dale A. Wood

    The Pentagon Building in northern Virginia is actually made of five pentagonal rings nested inside each other. Those rings have been given letters of the alphabet {A, B, C, D, E}. So, if someone with the Department of Defense says, “I work in the E-ring,” then that gives you a start on how to find him/her. Then if you have their room number, you can figure out where to go.
    (I lived in the Washington area for seven years, so I found out about it.)

  • Dale A. Wood

    I tried to think of names that begin with all of the missing letters of the alphabet in the list given by Mr. Nichol. For the letter “Q”, all I can think of are the “Q-ship”, an unusual kind of warship of World War I, and “Q-fever” caused by an African microbe and formerly proposed for the wretched idea of a weapon in bacteriological warfare. (At the time of President Nixon, the U.S. unilaterally abandoned all research and stockpiling in offensive bacteriological warfare. Most potential enemies and allies followed suit, but there is still fear of anthrax or smallpox being used by maniacs.)
    For the letter “K”, there is the “K-truss”, used by civil engineers in building bridges: truss bridges and suspension bridges.

  • Dale A. Wood

    N-bomb – an explosive nuclear weapon of any kind, whether using uranium, plutonium, hydrogen, or any other element.
    There was a hypothetical “atomic ray” that was supposedly observed by a physicist in Nancy, France (in Alsace-Lorraine), and hence given the name “N-ray”. Most physicists could not see N-rays (with the specified equipment), but some did claim to confirm them.
    Then, an American physicist named Dr. Wood who was visiting Nancy proved conclusively that “N-rays” were a huge mistake and falsehood. The scientists who claimed to have seen N-rays were all fooling themselves.

  • Dale A. Wood

    In the sciences and mathematics, people often use the letters of the Greek alphabet in the same way. Since I can’t type Greek here, I’ll just spell a few of them out:
    alpha-particle, alpha-ray, beta-particle, beta-ray, gamma-ray, delta-ray, mu-meson, pi-meson, kappa-meson, omicron-particle, sigma-particle, tau-neutrino, and the chi-squared distribution, which I can write as the X-squared distribution, or the X^2 distribution, where X = “the Greek letter chi”. The X-squared distribution is very important in statistics, and especially in determining if some kinds of statistical analysis are valid or not. Most people do not understand that there are tests for validity in statistics – thus it isn’t just some kind of guesswork.

  • Dale A. Wood

    Nicknames for geographical locations which fit this format:
    A-town = Atlanta, Georgia
    B-town = Boston, Massachusetts, a.k.a. “Beantown”
    Chi-town = Chicago, Illinois
    G-town = Georgetown in the District of Columbia, Delaware, or Kentucky
    J-town = Jacksonville or Jackson in several different states
    K-town = Knoxville, Tennessee
    P-town = Philadelphia
    Q-town = Quebec City ???
    T-town = Tuscaloosa, Alabama

  • Dale A. Wood

    In German, a U-bahn is an American-style subway, not a British one.
    A U-bahn is an underground commuter railroad. In Germany, there are also the S-bahn, another kind of a railroad.
    This kind of abbreviation is popular in German, which definitely does have long words. Some of these names are in chemistry and rocketry: A-stoff, B-stoff, … X-stoff, Z-stoff. “Stoff” is the German word for “stuff”, and it also means “material”, including the kinds of fabric that are cut and sewn into clothing, tents, etc.
    A lot of those “X-stoff” kinds of words are different concentrations of hydrogen peroxide. As the percentage of hydrogen peroxide goes up, these become more and more explosive and dangerous. During the Nazi era, these were used as rocket fuel in the pioneering experiments. Americans like Robert Goddard used somewhat less dangerous “stuffs”, like gasoline, concentrated alcohol, and liquid oxygen. One little mistake with rocket fuel will ruin your whole day!! For sure.

  • Dale A. Wood

    There is a subatomic particle called the K-meson, and this is often called the “kaon”. Likewise for the mu-meson and the pi-meson, whose names were eventually shortened to “muon” and “pion”.
    It was also found that the muon isn’t a meson at all, but rather a kind of heavyweight electron, and an even heaver kind is called the “tauon” or “tau-meson”. Nobody knows why Mother Nature needed muons or tauons.
    All real mesons consist of two quarks, plus the necessary “gluons”.
    Protons, neutrons, and the related particles consist of THREE quarks, plus the necessary gluons. This family of subatomic particles is called the “baryons”.
    So, I have covered the letter K (or kappa) and the Greek letter “tau”.

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