Answer: aggrade

AnswerCrossword Clue
AGGRADEBuild up, as the bank of river.
AGGRADEBuild up: Geol.
AGGRADEBuild up
AGGRADEFill, as with silt
AGGRADEBuild up a slope
aggradeto raise the grade or level of (a river valley, a stream bed, etc.) by depositing detritus, sediment, or the like
aggradeto fill (a stream bed) with sediment