What is Boston Bluff?
1.
While driving, the act of entering traffic from a side street, driveway, or parking lot by inching forward into the roadway a few more inches after each passing car has _not_ stopped to let you onto the street -- eventually placing your vehicle so far into the roadway that the next oncoming car _has to_ stop to let you in.
"Dude, it's rush hour -- if you don't use a Boston bluff, we'll never get out of here."
See