noun
A gradual shifting of a riverÂ’s course, causing it to
withdraw from its banks and/or to lower its level. The newly created dry land,
if the retreat is permanent, becomes the property of the owner of the adjoining
property; the changing of a propertyÂ’s boundary line by the erosion of land by
a river or stream. See also
accretion,
avulsion, and
dereliction.