Aggradational is a geological term that refers to the process of sediment accumulation. Synonyms for aggradational include sedimentary, depositary, accretionary, sedimentologic, and alluvial. Sedimentary refers to rocks that are formed through the accumulation of sediment. Depositary describes a place where deposits are stored. Accretionary refers to the growth or increase of something by adding layers. Sedimentologic relates to the study of sedimentary rocks. Alluvial refers to the deposition of sediments by flowing water, typically in a river, floodplain, or delta. These synonyms can be used interchangeably with aggradational to describe the process of sediment accumulation in geological formations.