something that makes or causes something else to grow or develop

Tourism has acted as a stimulant to the country's economy. 旅游业成为该国经济发展的一个促进因素。

a substance, such as a drug, that makes the mind or body more active

Caffeine, which is found in coffee and tea, is a mild stimulant. 咖啡和茶中含有的咖啡因是轻度兴奋剂。