coast
1. Literally, that part of a body of water that meets the shore.

2. Slang, a locale that has been cased, dating from the era of sea pirates.
1. The California shore meets the Pacific coast.

2a. The pirates left, so the coast is clear.

2b. The Navy left, so the coast is clear for pirating.

2c. We cased the joint, and the coast is clear.