bay salt

from The Century Dictionary.

• noun Coarse-grained salt: properly applied to salt obtained by spontaneous or natural evaporation of sea-water.

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

• Salt which has been obtained from sea water, by evaporation in shallow pits or basins, by the heat of the sun; the large crystalline salt of commerce.

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

• noun Salt obtained from seawater by evaporation in shallow pits or basins, by the heat of the sun.