n. A nearly flat coastal area, alternately covered and exposed by the tides, and consisting of unconsolidated sediments.
tid′al flat`
n. tideland that is flat and often marshy. [1955–60]
tidal flat
tidal flat
[′tīd·əl ′flat] (geology) A marshy, sandy, or muddy nearly horizontal coastal flatland which is alternately covered and exposed as the tide rises and falls.