rain·for·est or rain forest 
(rānfôr′ĭst, fŏr′-)
(rānfôr′ĭst, fŏr′-)n.
A dense evergreen forest with a minimum annual rainfall of approximately 180 centimeters (71 inches). Rainforests are found chiefly in the tropics but also occur in temperate regions, where the rainfall amount is somewhat lower.