According to the Vegetarian Society, a vegetarian is someone who lives on a diet of grains, pulses, nuts, seeds, fruit and vegetables with or without the use of dairy products and eggs.
A vegetarian does not eat any meat, poultry, game, fish, shellfish or by-products of slaughter.
Lacto-ovo vegetarian: a vegetarian who eats dairy products and eggs but does not eat meat.
Lacto-vegetarian: a vegetarian who eats dairy products but avoids eggs.
Vegan: a vegetarian who does not eat dairy products, eggs or any other products that are derived from animals.