semi-arid land ecosystem The interacting system of a biological community and its non-living environmental surroundings in regions that have between 10 to 20 inches of rainfall and are capable of sustaining some grasses and shrubs but not woodland
semi-metal An element having some properties characteristic of metals and others of non-metals. Many metalloids give rise to an amphoteric oxide (e.g. arsenic or antimony) and many are semiconductors