1. City in Miami-Dade County, Florida.
2. Often used to describe both the city proper and it's surrounding metropolitan area within Miami-Dade County, although it's limits can vary from person to person (i.e. Someone from North Miami-Dade may not consider parts of South Miami-Dade's suburbs to be "Miami".) This is acceptable usage, since the city limits of Miami are small and its aggomeration of urbanized areas have long since spilled beyond it's original borders.
3. A place where people who live in Miami-Dade County, especially in it's suburban neighborhoods, invoke in order to make himself appear to be more "street-credible" than he actually is.
Note on #3: While North Miami-Dade tends to be rougher than South Miami-Dade in general(although there are some exceptions; e.g. Aventura, Miami Shores) people from the southern suburbs, especially adolescences tend to utilize the image projected by the grittier northern neighborhoods to project their own neighborhood as a rough and gritty place to live in, while in reality they live in a comfortable suburban enviroment.
1. I'm from Miami. (He actually does live in Miami)
2. I'm from Miami. (He actually lives in Kendall)
3. I'm from Miami! (He acutally lives in CocoPlum or Key Biscayne or some other place I've never been to)