Offensive words are often abbreviated for politeness, or decency. This is not limited to slang, or words that are always offensive- it can include words that are offensive to a certain party. For instance, abortion may be so offensive to a pro-life family that during normal conversation, if the pregnant daughter was to suggest getting an abortion, the mother would shout "HEY! Don't use the 'A' word in this house!"
This practice has existed for centuries. Some very common examples are below.
The "N Word" is often used to mean the word nigger, and is the title of a documentary.
The "F word" sometimes means fuck, but is also the name of a cooking show, The F-Word, and sometimes has even been used to mean feminism.
The L Word is the name of a TV series, but has also been used to mean love This is strange because the word usually imposes a positive effect on those who hear it, but positive or negative, it's a strong word, and sometimes those emotions aren't wanted in the conversation.