Expletive (noun)

1. An oath or swear word.
2. A word or phrase used to fill a sentence without adding to its meaning, such as "well" or "so" in the sentence "Well, I don"t know".
3. An interjection expressing surprise, anger, or some other emotion.

Origin:

Late middle english: from latin expletivus, from explet- "filled up", from the verb explere, from ex- "out" + plere "fill".

Examples:

1. He used a lot of expletives during the argument.
2. The expletive was bleeped out during the live broadcast.
3. He used expletives to express his frustration.
4. The expletives were not necessary in the conversation.
5. The use of expletives is considered inappropriate in most formal settings.