A large system of rift valleys in eastern Africa and the Middle East, forming the most extensive such system in the world and running for some 4,285 km (3,000 miles) from the Jordan valley in Syria into Mozambique. It is marked by a chain of lakes and a series of volcanoes, including Mount Kilimanjaro.
Definition of Great Rift Valley in US English:
Great Rift Valley
proper noun
A large system of rift valleys in eastern Africa and the Middle East, the largest in the world, that runs for about 3,000 miles (4,285 km) from the Jordan valley in Syria into Mozambique. It is marked by a chain of lakes and a series of volcanoes, including Mount Kilimanjaro.