Four-letter word

The mysteries of English orthography result in many words in that language appearing in writing with four letters. This expression does not refer to all such words.

Some few of those words, scorned in polite society but redolent with earthy Anglo-Saxon pungency, have become known simply as four-letter words. Common popular or slang terms for excretory functions, sexual activity or genital body-parts (for example) thus have their own artificial and euphemistic linguistic category.

Common four-letter words (in this sense) include: cunt, damn, fuck, shit, and twat. (There are at least ten others.) All of these words are considered vulgar or offensive. See profanity.

A similar tradition occurs in Dutch although it's using only three letters and are in fact three-letter-words: (kut, pik, lul, gvd)

In French, the word merde (shit) is sometimes referred to as les cinq lettres (the five letters).

Another interesting meaning of four-letter word (in Greek, tetragrammaton) is "the name of God", that is, יהוה (commonly transliterated as "YHWH"), which was supposed never to be spoken aloud, now known as Yahweh or Jehovah.

Quotation

Good authors too who once knew better words

Now only use four-letter words

Writing prose.

Anything goes.

— Cole Porter, "Anything Goes"

The fact that "love" is literally a four-letter word has been used in several popular songs, including "Love Is Just A Four-letter Word" written and performed by Bob Dylan, and "Four Letter Word" written by Ricky & Marty Wilde and performed by Kim Wilde.