four-letter word

Etymology
From the frequency of the most common swear words being composed of or spelt with four letters.

Noun

 * 1) A reference to any of several of the strongest English swear words that are also four letters long, especially those composing the so-called seven dirty words.
 * 2)  A swear word or any words considered to be taboo in a given scenario (regardless of length of word).
 * 1)  A swear word or any words considered to be taboo in a given scenario (regardless of length of word).
 * 1)  A swear word or any words considered to be taboo in a given scenario (regardless of length of word).