Jam-up and Lock up

Jam-up noun - A crowded mass (as of cars) that impedes or blocks movement.

Lock up and jam-up are semantically related. In some cases you can use "Lock up" instead a verb phrase "Jam-up".

Lock up verb - To put in or as if in prison.

Jam-up and lock up are semantically related. Sometimes you can replace phrase "Jam-up" with "Lock up", this terms are similar.