1.) Noun. Used in written conversation to express disbelief, incredulity, or lack of response to an outrageous statement.
2.) Noun. Written proceeding a sentence to add implication to that sentence.
1.) Person A: Yes, I did eat the bread that was growing mold. I was that hungry!
Person B: ....
2.) Person A: Have you heard back from the doctor about that rash?
Person B: Yes..... Implication: (And I have an STD) or (And I would prefer not to talk about it).
It's like "..." except with an additional "." at the end. Unlike "..." however, it's used to say "Yeah, I'm listening go on" instead of an akward silence (like ...).
It originates from the NES game GOLGO 13: Top Secret Episode, a game about a hitman where the main character always reponds to his clients by saying "..." as a way of saying "yeah go on, I'm listening."
Duke Togo stood there quietly. saying "...." while waiting for his client to finish talking.