ˈrain ˌforest BrE AmE , rain‧for‧est /ˈreɪnfɒrəst, ˈreɪnfɒrɪst $ -fɔː-, -fɑː-/ noun [uncountable and countable]
a tropical forest with tall trees that are very close together, growing in an area where it rains a lot:
the destruction of the rain forest