Emily Dickinson Lexicon

AL-LU'VI-ON, or AL-LU'VI-UM, n. [L. alluvio, of ad and lavo or luo, alluo, to wash. See Lave.]

1. The insensible increase of earth on a shore, or bank of a river, by the force of water, as by a current or by waves. The owner of the land thus augmented has a right to the alluvial earth.
2. A gradual washing or carrying of earth or other substances to a shore or bank; the earth thus added.
3. The mass of substances collected by means of the action of water. In this alluvium was found the entire skeleton of a whale. – Buckland.