What is the definition or description of: vegetarian diet?

No meat diet: It is a diet where the person does not eat meat (red meat, poultry, fish, etc.). It may also include abstention from by-products of animal slaughter, such as animal-derived rennet and gelatin.

Plant based: It is a plant based diet including fruits, vegetables, cereals, grains, nuts, seeds and mushrooms. Those who eat eggs are called ovo vegetarian. And those who include milk in their diet as well are lacto-ovo-vegetarian as apposed to strict vegans as outlined above.