1. coastal lands that are covered and uncovered by the rise and fall of tides
Usage: geography; legal
2. submerged lands extending seaward from the low-water mark, especially as they relate to mineral rights and jurisdiction
Usage: legal; oil industry

Examples

• The tidelands are rich feeding grounds for migrating birds.
• Oil companies sought drilling rights in the offshore tidelands.
• The Supreme Court ruled on federal versus state control of tidelands.
• Marine biologists study the unique ecosystem of the tidelands.
• California’s tidelands contain valuable petroleum deposits.
• The tidelands are exposed at low tide and submerged at high tide.