inlet

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A recess, such as a bay or cove, along a coast.
• noun A stream or bay leading inland, as from the ocean; an estuary.
• noun A narrow passage of water, as between two islands.
• noun A drainage passage, as to a culvert.
• noun An opening providing a means of entrance or intake.

from The Century Dictionary.

• noun A passage or opening by which an inclosed place may be entered; place of ingress; entrance.
• noun A waterway leading into a sea or lake, and forming part of it; a strip of water running from a larger body into the land; a creek; a channel.
• noun Inserted material.
• To let in; admit.
• To insert; inlay.

from the GNU version of the Collaborative International Dictionary of English.

• noun A passage by which an inclosed place may be entered; a place of ingress; entrance
• noun A bay or recess, as in the shore of a sea, lake, or large river; a narrow strip of water running into the land or between islands.
• noun That which is let in or inlaid; an inserted material.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb transitive To let in; admit.
• verb transitive To insert; inlay.
• noun A body of water let into a coast, such as a bay, cove, fjord or estuary.
• noun A passage that leads into a cavity.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun an arm off of a larger body of water (often between rocky headlands)
• noun an opening through which fluid is admitted to a tube or container