four-letter word

Từ điển Oxford Advanced Learner 8th

ˌfour-letter ˈword [four-letter word four-letter words] BrE NAmE noun
a short word that is considered rude or offensive, especially because it refers to sex or other functions of the body
Syn: ↑swear word
•The play is full of four-letter words.

Culture:
swear words
Many people find swearing offensive and it is safest to avoid doing it. Swear words are used mainly in two situations: to relieve feelings of anger and frustration when something bad happens, and to show your anger to somebody who has upset you. The words used often lose their normal meaning and act simply as a way of expressing feelings. Swear words are usually short and have a strong sound that can be spat out. Since many swear words have four letters they are sometimes called four-letter words.
Like slang expressions, swear words come in and out of fashion and over time often lose their power to shock. They are replaced by new, stronger words, though the outdated words may continue to be used by older people. Exclamations such as Drat!, Blow! and Blast!, for instance, are now rarely heard among young people, although the older generation still use them.
Swear words are also called bad language and swear words that refer to sex or to bodily functions are called dirty language or obscene language. Other swear words have a religious origin and are sometimes called oaths. Many were used for cursing (= asking for the help of a supernatural power to punish somebody). Often, obscene and religious language are combined, as in the expression Fucking hell! A person who is very angry and using a lot of swear words may be said to be cursing and swearing or effing and blinding.
The most common oaths include Heavens above! and Oh, Lord!, and the stronger Damn!, God! Christ!, Jesus Christ! and For Chrissake! which may cause offence to Christians. Many people are upset when they hear obscene language. The strongest swear words include Fuck! and Shit! Other things people say when they are angry or annoyed are Bugger! (BrE), Dang! (AmE) and Darn! (AmE). Swear words used to insult people include Bastard!, Bitch!, Son of a bitch!, Asshole!, Cunt! and, especially in the US, Motherfucker!
Expressions with ‚it’ added such as in Damn it! and Fuck it! are used as alternatives to the single word. When ‚off’ is added, as in Fuck off!, its derivative Eff off!, Piss off! and Bog off!, the expressions take on the meaning of ‚Go away!’
The words fucking, frigging, chuffing (BrE) and freaking (AmE) are used as intensifiers (= words that strengthen the meaning of a word) in expressions like Fucking hell! and You’re a freaking liar! Damn, and the stronger bloody (BrE), are used before nouns, as in a damn nuisance and You bloody fool!
Some people feel strongly that it is always wrong to swear and do not like to hear others swearing. The angrier the tone of voice, the more unpleasant and frightening it is likely to be. Other people swear only when a situation makes them very upset. But some people use swear words in almost every sentence. People may apologize if they use a swear word in front of somebody who does not approve of swearing, possibly by saying ‚Pardon my French’. Some people may use an ordinary word or a mild swear word in place of the stronger one they would really like to say. People may say Sugar!, for example, instead of Shit!, though this is now rather old-fashioned. Children are usually not allowed by their parents to swear, and so often find bad words especially interesting.
When strong swear words are spoken on television they may be bleeped out (= replaced by a high-pitched noise) to avoid causing offence. Some words may not be used during times when children might hear them. Film classifications are based partly on the language used in them. Newspapers and books may leave out some of the letters in swear words, for example printing fuck as f***. As a result this is sometimes known as ‚the F-word’.
See also ↑slang
.