Lagoon and Sump

Lagoon noun - A body of water cut off from a larger body by a reef of sand or coral.

Sump and lagoon are semantically related in septic tank topic. In some cases you can use "Sump" instead a noun "Lagoon".

Sump noun - A well or other hole in which water has collected.

Lagoon and sump are semantically related in septic tank topic. Sometimes you can use "Lagoon" instead a noun "Sump".