1. noun
Vegetarian Society A society formed at Manchester in 1847, to promote the use of cereals, pulse, and fruit, as articles of diet; and to induce habits of abstinence from fish, flesh, and fowl, as food.
b) An animal that eats only plants; a herbivore.
vegetarian [...] One who abstains from animal food, living exclusively on vegetables, milk, eggs, and the like. The more strict vegetarians eat vegetables and farinaceous food only, abstaining from eggs, butter, milk, and in some cases, honey.
2. adjective
Of or relating to the type of diet eaten by vegetarians (in all senses).
Wikipedia foundation.