Pronunciation: (sem"ē-ar'id, sem"ī-), [key]
—adj.(of a region, land, etc.)
characterized by very little annual rainfall, usually from 10 to 20 in. (25 to 50 cm): the struggle to raise vegetables in semiarid regions.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.