The word vegetarian is derived from the Latin meaning vegetus whole, healthy, fresh, alive. The mention in general those who do not eat meat before the year 1847 as 'Pythagoreans' or follow the 'Pythagorean System'. The original definition of 'vegetarian' is with or without eggs or dairy products. This definition is still used today by the Vegetarian Society.
If we look at world history, vegetarianism has existed long before BC, as implemented by the communities living in India and China. They run the practice aims to respect and love all living things.