Dictionary
ag•grade
Pronunciation: (u-grād'), [key]—
v.t., -grad•ed, -grad•ing.
Phys. Geog.
to raise the grade or level of (a river valley, a stream bed, etc.) by depositing detritus, sediment, or the like. Cf.
degrade.Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.