Originally meaning when a person is about to engage in sexual activity and a person (family member, friend, child etc.) stops any chance of doing so. This can also be applied to any day to day non-sexual activity. Such as going out with friends, smokingbud, etc.
"Dude, I was guna get some ass, but then her best friend, who I think is a dyke and totally has a crush on her, cockblocked me."
"Fuck man, we were going to the movies, but then my mom cockblocked me."
The act or reactive measure when the opposite sex makes eye-contact with you and then proceeds to plug in their iPod as a defense mechanism to prevent you from making a move on them.
Josh: I saw this girl on the bus and was going to hit on her, then she busted out her iPod.
A phenomenon in film/television series, most notably streaming series, where the main premise is drawn out to such a point that it takes an entire season or more to get the parts of the series the audience is actually interested in seeing.
For example, if a series is titled "Surf Dracula," a majority of viewers would tune in expecting to see Dracula surfing by the first or second episode. However, the entire first season would instead be tedious padding and backstory before finally ending with Dracula surfing in the last five minutes of the season finale.
I watched "Smallville" on Netflix the other day. Dude, it was ten seasons of filler before he finally flew! Major Surf Dracula Syndrome!