Pronunciation: (lu-gOOn'), [key]
1. an area of shallow water separated from the sea by low sandy dunes. Cf. laguna.
2. Also,lagune.any small, pondlike body of water, esp. one connected with a larger body of water.
3. an artificial pool for storage and treatment of polluted or excessively hot sewage, industrial waste, etc.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.