Let's break it down:

Survival: being able to adapt to any situtation, as well as being able to do the impossible in order to see things through to the very end.:hat

Horror: anything that has to do with fear, especially our deepest and darkest fears; fears that have been with us since our cave-dwelling days.

But the two together and you get this:

Survival Horror: being able to adapt to the embodiment of our deepest fears. Being able to survive things that man should not have to go through. Being able to stand tall when the world falls around you.:hat

Resident Evil, Doom, Quake, Dead Rising, Slient Hill, Evil Dead, and countless other games and movies fit this definition.
"I've been a bad, bad girl." Red Queen, Resident Evil