Word forms: plural rainforestsregional note: in AM, also use rain forest
variable noun
A rainforest is a thick forest of tall trees which is found in tropical areas where there is a lot of rain.
There is worldwide concern about the destruction of the rainforests.
...a vast area of tropical rainforest.
rainforest in British English
(ˈreɪnˌfɒrɪst)
noun
dense forest found in tropical areas of heavy rainfall. The trees are broad-leaved and evergreen, and the vegetation tends to grow in three layers (undergrowth, intermediate trees and shrubs, and very tall trees, which form a canopy)