This noun is believed to be derived from legend. None know it's true origin, however it is used in a variety of ways. It is also fabled to have once been a lost or omitted mythical creature.

1. A random phrase, typically used to disregard someone when you don't feel like answering.
2. A substitute for a swear word.
3. Used for randomly blurting out in a specifically funny or unexpected situation or time in conversation. A good tool for breaking the ice and/or making yourself look like an idiot.