A gyre is another name for a swirling vortex. Ocean gyres are large swirling bodies of water that are often on the scale of a whole ocean basin or 1000 s of kilometers across (hundreds to thousands of miles across).
Lean meats are meats with a relatively low fat content. Skinless chicken and turkey and red meat, such as pork chops, with the fat trimmed off are examples of lean meat.
Venison is a lean type of meat. Venison is meat that comes from deer. The biggest difference between beef and venison is the way they are raised. Beef cattle is raised by human hands, where deer is wild game. From a nutrient perspective, these meats are similar in some areas and different in others.