1Submerged or flooded; especially designating a stretch of coastal land submerged as a result of a relative rise in sea level; of or relating to such land.
Of a plant: growing entirely under water; = "submerged".
A submergent water plant.
Mid 19th century; earliest use found in Edward Moor (1771–1848), writer on Hindu mythology. From submerge + -ent, after emergent.