Inlet and Siamese connection

Inlet noun - A part of a body of water that extends beyond the general shoreline.

Siamese connection and inlet are semantically related. In some cases you can replace phrase "Siamese connection" with "Inlet", this terms are similar.

Siamese connection noun - An inlet with two or more couplings to which a hose can be attached so that fire engines can pump water into the sprinkler system of a building.

Inlet and siamese connection are semantically related. You can use "Inlet" instead a noun phrase "Siamese connection".