purple-lining
Occurs when one is using the Maps app on an iPhone. Instead of actually reading the directions, the person simply makes sure that their blue location dot remains along the path of the purple directions line.
Example:
"Bro, what exit are you supposed to get off at?"
"No idea, man. I'm straight purple-lining right now."
"Bro, what exit are you supposed to get off at?"
"No idea, man. I'm straight purple-lining right now."