To excite is to stimulate, animate, or energize. The return of your favorite TV show might excite you, and winning millions of dollars in the lottery will definitely excite you.
While a new book by a beloved author excites one person, and an extra scoop of ice cream excites another, it might take something like a free trip to Hawaii to excite you. In quantum mechanics, the word excite takes on a more scientific meaning: to raise something, like an atom or an electron, to a higher level of energy. The Latin root of excite is excitare, "rouse, call out, or summon forth."