کاربرد واژهای خوشایند به جای واژهای که دارای معنای ضمنی ناخوشایند است را حُسن تَعبیر یا بـِهگویی میگویند. واژهای با معنای خوشایند که به جای واژهای با معنای ناخوشایند به کار برود را بهواژه میگویند. استفاده از اصطلاحاتی نظیر «سرویس بهداشتی» به جای «توالت» یا «شکر خوردم» به جای «گه خوردم»؛ یا «روشندل» به جای «نابینا» نمونههایی از این فرایند زبانی هستند.
بهگویی نوعی فرایند زبانی است که در آن عبارات و واژههای ناخوشایند، توهینآمیز، یا دشواژه جای خود را به جملات و کلماتی میدهند که بار معنایی منفی کمتری دارند. برخی حسن تعبیرها به منظور سرگرمی و برخی دیگر برای مثبت جلوه دادن یک رویداد منفی استفاده میگردد.
بیشتر واژههای بهگویانه در زبان فارسی در حوزه مسائل مربوط به مرگ، مسائل جنسی، مواد زاید بدن، تبلیغات، ناتواناییهای جسمی، اعضای بدن، بیماریهای روانی، مواد مخدر، ناسزاها و تجارت بهکار میروند.
ابزارهای زبانی بهکار رفته در ساخت بهگوییها در زبان فارسی عبارتاند از تکرارشوندگی، حذف، وامگیری واژگانی، استلزام معنایی، استعاره، مجاز، تضاد معنایی، کمگفت، مبالغه، اطناب، رَدّ خُلف، واژههای مبهم، گسترش معنایی و عبارات اشارهای.
A euphemism // is an innocuous word or expression used in place of one that may be found offensive or suggest something unpleasant. Some euphemisms are intended to amuse, while others use bland, inoffensive terms for concepts that the user wishes to downplay. Euphemisms may be used to mask profanity or refer to taboo topics such as disability, sex, excretion, or death in a polite way.
Euphemism comes from the Greek word euphemia (εὐφημία) which refers to the use of 'words of good omen'; it is a compound of eû (εὖ), meaning 'good, well', and phḗmē (φήμη), meaning 'prophetic speech; rumour, talk'. Eupheme is a reference to the female Greek spirit of words of praise and positivity, etc. The term euphemism itself was used as a euphemism by the ancient Greeks; with the meaning "to keep a holy silence" (speaking well by not speaking at all).
Reasons for using euphemisms vary by context and intent. Commonly, euphemisms are used to avoid directly addressing subjects that might be deemed negative or embarrassing.
Euphemisms are also used to downplay the gravity of large-scale injustices, war crimes, or other events that warrant a pattern of avoidance in official statements or documents. For instance, one reason for the comparative scarcity of written evidence documenting the exterminations at Auschwitz, relative to their sheer number, is "directives for the extermination process obscured in bureaucratic euphemisms".
Euphemisms are sometimes used to lessen the opposition to a political move. For example, according to linguist Ghil'ad Zuckermann, Israeli Prime Minister Benjamin Netanyahu used the neutral Hebrew lexical item פעימות peimót ("beatings (of the heart)"), rather than נסיגה nesigá ("withdrawal"), to refer to the stages in the Israeli withdrawal from the West Bank (see Wye River Memorandum), in order to lessen the opposition of right-wing Israelis to such a move.:181 The lexical item פעימות peimót, which literally means "beatings (of the heart)" is thus a euphemism for "withdrawal".:181
The act of labeling a term as a euphemism can in itself be controversial, as in the following two examples:
Phonetic euphemism is used to replace profanities, diminishing their intensity. Modifications include:
Figures of speech
The use of a term with a softer connotation, though it shares the same meaning. For instance, screwed up is a euphemism for fucked up; hook-up and laid are euphemisms for sexual intercourse.
There is some disagreement over whether certain terms are or are not euphemisms. For example, sometimes the phrase visually impaired is labeled as a politically correct euphemism for blind or a blind person. However, visual impairment can be a broader term, including, for example, people who have partial sight in one eye, those with uncorrectable mild to moderate poor vision, or even those who wear glasses, groups that would be excluded by the word blind.
Words from a foreign language
Expressions or words from a foreign language may be imported for use as a replacement for an offensive word. For example, the French word enceinte was sometimes used instead of the English word pregnant. This practice of word substitution became so frequent that the expression "pardon my French" was adopted in attempts to excuse the use of profanity.
Euphemisms may be formed in a number of ways. Periphrasis, or circumlocution, is one of the most common: to "speak around" a given word, implying it without saying it. Over time, circumlocutions become recognized as established euphemisms for particular words or ideas.
To alter the pronunciation or spelling of a taboo word (such as a swear word) to form a euphemism is known as taboo deformation, or a minced oath. In American English, words that are unacceptable on television, such as fuck, may be represented by deformations such as freak, even in children's cartoons. Feck is a minced oath originating in Hiberno-English and popularised outside of Ireland by the British sitcom Father Ted. Some examples of rhyming slang may serve the same purpose: to call a person a berk sounds less offensive than to call a person a cunt, though berk is short for Berkeley Hunt, which rhymes with cunt.
Bureaucracies frequently spawn euphemisms intentionally, as doublespeak expressions. For example, in the past, the US military used the term "sunshine units" for contamination by radioactive isotopes. An effective death sentence in the Soviet Union during the Great Purge often used the clause "imprisonment without right to correspondence": the person sentenced would be shot soon after conviction. As early as 1939, Nazi official Reinhard Heydrich used the term Sonderbehandlung ("special treatment") to mean summary execution (most likely by hanging) of persons viewed as "disciplinary problems" by the Nazis even before commencing the systematic extermination of the Jews. Heinrich Himmler, aware that the word had come to be known to mean murder, replaced that euphemism with one in which Jews would be "guided" (to their deaths) through the slave-labor and extermination camps after having been "evacuated" to their doom. Such was part of the formulation of Endlösung der Judenfrage (the "Final Solution to the Jewish Question"), which became infamous to the entire world during the Nuremberg Trials.
A euphemism may itself devolve into a taboo word, through the linguistic process known as semantic change (specifically pejoration) described by W. V. O. Quine, and more recently dubbed the "euphemism treadmill" by Harvard professor Steven Pinker. For instance, toilet is an 18th-century euphemism, replacing the older euphemism house-of-office, which in turn replaced the even older euphemisms privy-house and bog-house. In the 20th century, where the words lavatory or toilet were deemed inappropriate (e.g. in the United States), they were sometimes replaced with bathroom or water closet, which in turn became restroom, W.C., or washroom. Another example in American English is the replacement of colored with Negro and then Black and then African American.
Euphemisms are at risk of being misunderstood and used literally by young children who are acquiring language, and by older people who are learning a foreign language. An example is the "pregnant fireman" type of children's solecism, where a child might hear someone define pregnancy euphemistically as "carrying a child," then mistakenly extend that meaning and refer to a fireman literally carrying a child as pregnant. 
In popular culture
Doublespeak is a term sometimes used for deliberate euphemistic misuse of words to distort or reverse their meaning, as in a "Ministry of Peace" which wages war, and a "Ministry of Love" which imprisons and tortures. It is a portmanteau of the terms Newspeak and doublethink, which originate from George Orwell's novel Nineteen Eighty-Four.
The word euphemism itself can be used as a euphemism. In the animated TV special Halloween Is Grinch Night (see Dr. Seuss), a child asks to go to the euphemism, where euphemism is being used as a euphemism for outhouse. This euphemistic use of euphemism also occurred in the play Who's Afraid of Virginia Woolf? where a character requests, "Martha, will you show her where we keep the, uh, euphemism?"
In Wes Anderson's film Fantastic Mr. Fox, the replacement of swear words by the word cuss became a humorous motif throughout the film.
In Tom Hanks's web series Electric City, the use of profanity has been censored by the word expletive. "[Expletive deleted]" entered public discourse after its notorious use in censoring transcripts of the Watergate tapes.
In Isaac Asimov's Foundation series, the curses of the scientist Ebling Mis have all been replaced with the word unprintable. In fact, there is only one case of his curses being referred to as such, leading some readers to mistakenly assume that the euphemism is Ebling's, rather than Asimov's. The same word has also been used in his short story "Flies".
In Battlestar Galactica (2004), use of the words "frak" and "frakking" was directly substituted for the English slang words "fuck" and "fucking", confounding the censors. Other science fiction series have similarly used word substitution to avoid censorship, such as "frell" instead of "fuck" in Farscape, "gorram" and "rutting" instead of "goddamn" and "fucking" in Firefly, and "frag" instead of "fuck" in Babylon 5. The Good Place takes this word substitution to its logical extreme, replacing all profanities with similar-sounding English words under the premise that such words may not be spoken in a perfect afterlife in order to avoid making anyone uncomfortable; "son of a bitch" becomes "son of a bench", "bullshit" becomes "bullshirt", and "fuck" becomes "fork".