snarl up

snarl up (third-person singular simple present snarls up, present participle snarling up, simple past and past participle snarled up)

1. (transitive) to entangle
2. (intransitive) To become tangled; to become entangled
3. (transitive) To block (traffic); to cause (traffic) to be congested.
4. (intransitive, of traffic) to become congested.
5. (transitive) To put into disarray; contort; confuse; muddle up