10 Reverse Terms That Found Their Place in the Dictionary

While a palindrome reads the same backward and forward, a semordnilap forms a completely different word when reversed, such as stressed becoming desserts or diaper turning into repaid. Interestingly, the term semordnilap is itself a semordnilap. However, unlike most semordnilaps that occur by chance, a word deliberately formed by reversing another is known as an ananym.

Reversing words to create new ones is more common than you might think. This method has been used to devise place names like Adanac in Canada and Adaven in Nevada, as well as personal names such as Segna, derived from Agnes, and Nevaeh, a reversal of heaven, which became a popular girls' name in the U.S. Brands like Harpo Productions, founded by Oprah Winfrey, also employ this technique. Authors often use ananyms for fictional settings and characters, such as Samuel Butler’s Erewhon (a twist on nowhere) or Dylan Thomas’s Under Milk Wood, set in the fictional village of Llareggub (a cheeky reversal of “bugger all”). Even in films, like the 1943 classic Son of Dracula, the character Count Alucard hints at his true identity through his name.

Beyond brand names and proper nouns, several ananyms and semi-ananyms have successfully entered the dictionary—including the 10 examples detailed here.

1. Yob

During the 19th century, back-slang emerged as a playful linguistic trend, flipping letters or sounds to create humorous substitutes for common words. For instance, fire turned into “erif,” cabbage became “edgabac,” a policeman was called a “namesclop,” and a birk referred to a house (from reversing “crib”). Although many words from Victorian back-slang have faded, the term yob, meaning “boy,” remains in use today.

2. Yarg

Yarg is a distinctive cow’s-milk cheese produced in Cornwall, known for being encased in nettle leaves during its maturation process. The recipe is attributed to a local dairy farmer, and the name comes from reversing his surname, Gray.

3. Mho

While the ohm measures electrical resistance, its reverse, the mho, quantifies electrical conductance. Symbolically, the ohm is represented by the Greek letter omega (Ω), whereas the mho uses an inverted omega. However, the mho isn’t widely recognized in scientific circles, as the siemens is the official SI unit for conductance.

4. Daraf

Similar to the relationship between mho and ohm, the daraf is a unit of electrical elastance formed by reversing the term farad, the SI unit of capacitance. Like the mho, the daraf isn’t commonly used, with the “reciprocal farad” being its accepted alternative.

5. Therblig

In 1921, American engineer FB Gilbreth and his wife Lillian released a groundbreaking study on workplace efficiency, pioneering the first time-and-motion analysis. By studying bricklayers, Gilbreth proposed that all workplace tasks could be broken down into 16 fundamental movements: search, find, select, grasp, transport loaded, position, assemble, use, disassemble, inspect, pre-position, release, transport empty, rest to combat fatigue, unavoidable delays, and avoidable delays (with later researchers adding a few more).

He named these basic action units therbligs—a partial reversal of his surname—and argued that employers aiming to maximize productivity should, as Lillian put it, “study your worker, identify their strengths, provide optimal tools and conditions, and success will follow.”

6. Yarooh

As per the Oxford English Dictionary, yarooh is “a playful, exaggerated depiction of a pain-induced exclamation.” It was coined by English author Charles Hamilton, who, writing as Frank Richards, introduced the term in his famous Billy Bunter comic series in 1909. As an expression of distress rather than joy, Hamilton devised the spelling yarooh by flipping the letters of hooray.

7. Atled

Coined in the mid-1800s, atled is the fitting name for an inverted version, ∇, of the Greek letter delta, Δ, used in mathematics to denote gradient. However, like the mho and daraf, the term atled isn’t widely adopted—its more common name is nabla, derived from a Greek harp with an inverted triangular shape.

8. Kayo

In 1920s slang, kayo served as a playful alternative to OK, created by reversing the sounds of the letters rather than the word OK itself (it may have been influenced by the boxing term KO, which was gaining popularity around the same time).

9. Allerednic

Coined by Oxford sociology professor Jonathan Gershuny, Allerednic syndrome represents the inverse of the Cinderella tale. It describes a successful woman who, upon marrying an equally accomplished man, sacrifices her career and status to become a full-time homemaker or mother. As Cherie Booth, wife of former British Prime Minister Tony Blair, once remarked, “You know the tale: the prince marries the princess and transforms her into a servant.”

10. Skoob

In the 1960s, British conceptual artist John Latham introduced the term skoob to describe a heap of books meant for destruction. As per the Oxford English Dictionary, Latham’s skoob was a protest against “the excessive reverence and spread of printed material,” while also providing a term for “the ritualistic burning of books.”