Meaning everything, anything, nothing and something. Used when you have nothing else to say. Such as a very boring conversation:
Person 1: Hi
Person 2: Hi
(about 5 minutes later)
Person 1: Oblomov.
Person 2: ....hmmm....
An extremely lazy person. (From Goncharov's novel, Oblomov)
Also, Oblomovism - somebody who suffrers from laziness.
Your ass is still on the couch? Damn, you just another Oblomov.