Does "chicano" mean "Mexican-American", or "Mexican living in the United States"?

Let me get this straight, do people in general's definition of "chicano" mean Mexican-American, as in imilated American w/Mexican ancestry, or a Mexican living in the United States that hasn't imilated? My mama, a self-proclaimed "true chicana", says if you haven't imilated, then you shouldn't call yourself chicano because you can't have "Mexican-American" without the "American". I mean damn, how could you be second generation and still not speak any damn English? What's your opinion on this?