snarl up

phrasal verb
snarled up; snarling up; snarls up

Definition of snarl up

 (Entry 1 of 2)

chiefly British
: to stop (something or someone) from moving or making progress Traffic was snarled up because of the parade.

snarl-up

noun

Definition of snarl-up (Entry 2 of 2)

chiefly British
: a situation in which one can no longer move or make progress a traffic snarl-up