Stimulant
Part of speech: adjective
Definition: Acting as a stimulant.
Part of speech: noun
Definition: A substance that acts to increase physiological or nervous activity in the body. Something that promotes activity, interest, or enthusiasm.
Stimulating
Part of speech: adjective
Definition: In a manner that stimulates.
Part of speech: verb
Definition: To encourage into action.
Example sentence: To me... San Francisco is an ideal city, intellectually stimulating and naturally beautiful. The oceans and forests are close enough to refresh the spirit; the architecture is always exciting.