seaboard

• seabord (obsolete)

From earlier sea-bord, perhaps continuing (with change in meaning) Middle English see bord (“porthole cover, seaward side”), equivalent to sea +‎ board.

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seaboard (plural seaboards)

1. The area bordering the sea; a coastline; a sealine.
   • 1948, Carey McWilliams, North from Mexico / The Spanish-Speaking People of The United States, J. B. Lippincott Company, page 25:

     While De Anza was exploring the Bay of San Francisco, seeking a site for the presidio, the American colonists on the eastern seaboard, three thousand miles away, were celebrating the signing of the Declaration of Independence.

• interseaboard

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