noun. A traffic jam in which no vehicular movement is possible, especially one caused by the blockage of key intersections within a grid of streets.

noun. A complete lack of movement or progress resulting in a backup or stagnation.

noun. A condition of total, interlocking traffic congestion on the streets or highways of a crowded city, in which no one can move because everyone is in someone else's way.

noun. On a smaller scale: the situation in which cars enter a signal-controlled intersection too late during the green light cycle, and are unable to clear the intersection (due to congestion in the next block) when the light turns red, thus blocking the cross traffic when it's their turn to go. Repeated at enough intersections, this phenomenon can lead to citywide gridlock.

noun. Figuratively and by extension, any paralysis of a complex system due to severe congestion, conflict, or deadlock.

noun. a traffic jam so bad that no movement is possible