To look the wrong way on a one way street when parallel or angle parking to make sure those idiots who drive the wrong way, don't hit you.
I was pulling out of the mall, but I had to do an idiot check because you know how those female drivers are.
On a cleanup after everyone thinks they have everything in the truck, someone goes back in to do one last thorough check.
Hey Scott go do an Idiot Check so we can get the hell out of here!
It's the once-over when leaving a hotel/friends house/somewhere where you won't be back for a while. Typically performed by one assigned person. For all those times when you think, "Man! i'm such an idiot! I forgot my ..."
"You take the bags to the car, and i'll do the idiot check."