Definition of "rain forest"

In recent years, the problems of the tropical rain forests have become an almost daily topic of conversation.

1997, Isamu Yamada, Tropical Rain Forests of Southeast Asia: A Forest Ecologist's View, page 292

Tropical rain forests have a greater variety of plants than any other place on Earth.

2002, Rain Forests of the World, Marshall Cavendish Corporation, page 449

Here's some more left-wing nonsense, this time from the environmentalists, the folks who gave us the rain forest. "Save the rain forest." They decided to call it that because they needed to raise money, and they knew no one would give them money to save a jungle. "Save the jungle" doesn't sound right.

2004, George Carlin, When Will Jesus Bring the Pork Chops?‎, New York: Hyperion Books, page 163

A large number of everyday foodstuffs that we enjoy today have their origins in the rain forests of the world.

2012, Peter Littlewood, Why Are the Rain Forests Being Destroyed?, page 10