A reference to any of several of the strongest English swearword that are also four letters long, especially those composing the so-called seven dirty words
A swearword or any words considered to be taboo in a given scenario, (regardless of how many letters are actually in the word or words in question)
To me, coming from you, 'Friend' is a four letter word. - Friend Is a Four-Letter Word, Cake.
A four-letter word is a short word that people consider to be rude or offensive, usually because it refers to sex or other bodily functions. = swear word. a word that is considered very rude and offensive, especially one relating to sex or body waste = swearword
any of several short English words (often having 4 letters) generally regarded as obscene or offensive