Clog up and Over-crowding

Clog up verb - Become or cause to become obstructed.

Over-crowding and clog up are semantically related In some cases you can replace phrase "Over-crowding" with "Clog up", this terms are similar.

Over-crowding noun - Excessive crowding.

Clog up and over-crowding are semantically related in clog topic. Sometimes you can use "Clog up" instead a verb phrase "Over-crowding".