(noun) Maneuver in which a driver blocks an entire lane of moving traffic in order to expedite a left turn or proceed straight; typically associated with Massachusetts and some Rhode Island drivers.
by PandaMan4lyfe May 14, 2011
Unlike a cock block, when anyone can jump the gun on you. When you're scouting a girl at a bar and your bro jumps in front of you to kick it.
Mike to Phil -"You see that hottie in the blue tank top over there by the bar? After I take a piss I'm on it."
**Mike goes to the bathroom and comes back to find his buddy Phil all over Jenna in the blue tank top**
Justin to Mike - "Oh man did you see that? Phil just layed a Boston Cock Block on you. Harsh!"
**Mike goes to the bathroom and comes back to find his buddy Phil all over Jenna in the blue tank top**
Justin to Mike - "Oh man did you see that? Phil just layed a Boston Cock Block on you. Harsh!"
by Zaphod Beebs June 3, 2010