"Navrigate? I never nagrivate! I'm just reminding you that Mom's house is on the left, and if you keep driving so fast you're going to miss the turn! That's not nagrivating! And signal this time! You always forget to signal until it's too late!"
The behavior made by a car-mounted or hand-held GPS navigation system when you fail to make a turn or otherwise leave the precalculated route. Typically this is done by endlessly saying "Recalculating..." and "Turn here" each side street you pass.