embayment

em- +‎ bay +‎ -ment

embayment (plural embayments)

1. A bay. (the water)
   • 1979, Cormac McCarthy, Suttree, Random House, p.121:

     The path climbed along a wall of purple sandstone above an embayment and in the sunlit shadows below him he could see the long cataphracted forms of gars lying in a kind of electric repose among the reeds.

2. The shoreline of a bay, an indentation in a shoreline. (the land, not the water)
3. A topographical feature that used to be a bay, like the Mississippi embayment.
4. The process by which a bay is formed.