A mountainous plateau region of northern South America, lying between the Orinoco and Amazon River basins, largely in south-eastern Venezuela and northern Brazil. Its highest peak is Roraima (2,774 m; 9,094 ft).
Definition of Guiana Highlands in US English:
Guiana Highlands
proper noun
A mountainous plateau region in northern South America that lies between the Orinoco and Amazon river basins, largely in southeastern Venezuela and northern Brazil.