From The Collaborative International Dictionary of English v.0.48 [gcide]:
Embayment \Em*bay"ment\, n.
A bay. [R.]
[1913 Webster]
The embayment which is terminated by the land of North
Berwick. --Sir W.
Scott.
[1913 Webster]
From WordNet (r) 3.0 (2006) [wn]:
embayment
n 1: an indentation of a shoreline larger than a cove but
smaller than a gulf [syn: bay, embayment]