According to Babylon, "chico" means "boy" in Spanish. Using the word "chico" implies that the subject is small, young or innocent, so the word is often used to describe small children.
Additionally, "chico" can be made feminine by changing the ending "o" to an "a," making it "chica" instead. In this context, it still refers to small, young and innocent subjects but now refers to a "girl" rather than a boy. In the Andes, "chico" is used as a slang verb with the meaning "to get drunk," but this usage is not very common anywhere else in the Spanish-speaking world.