English can be confusing because of terminology... As Americans we tend to shorten our words. We often refer to a large piece of meat as a "roast". We typically use this term when referring to a rump roast, round roast, or sirloin tip when making roast beef.
We also refer to pork shoulder or boston butt as pork roasts before they become roast pork.
Roast (Verb) - to cook food in an oven or over a fire. This slow roasting method at low heat is good for tougher cuts of meat; the lower heat breaks down connective tissue and prevents any gristle from getting too tough.
This method should not be used with choice or prime grades of beef, or the more tender cuts, as slow cooking more delicate cuts will make them mushy.
Also to heat nuts or coffee beans so that they become drier and browner, thus "roasted" nuts or "roasted" coffee beans.
Roast (Noun) - a piece of roasted meat