What exactly does barbecue mean?
In some parts of the country, such as Texas and Tennessee, your answer probably involves a method of slow-cooking with indirect heat. If you're a Northerner, you might just point to your backyard grill.
The word has different meanings, but a single origin.
When 17th-century Spanish explorers landed in the West Indies, they saw native people the Arawakan drying meat over a frame. The Arawakan called the wooden rack a barbacoa. The explorers borrowed the term.
Barbacoa soon came to name not only the frame but the process of cooking (not drying) meat. Now, of course, barbecue can name the cooking structure, the food, the cooking method, or the social occasion.