Vegetarian, simplest definition is non-meat-eater! The term 'Vegetarian' was coined in 1847 by Joseph Brotherton and others, at Northwood Villa in Kent, England. The occasion being the innaugural meeting of the Vegetarian Society of the United Kingdom. The word was derived from the Latin 'vegetus', meaning whole, sound, fresh, lively; Prior to 1847, non-meat eaters were generally known as 'Pythagoreans' or adherents of the 'Pythagorean System', after the ancient Greek 'vegetarian' Pythagoras.
Individuals have to develop their own program, What to eat, when to eat it, and why to eat it - plus simple, sensible guidelines on how to prepare, serve and digest the food you eat.

Different levels of vegeterians

Popular category of vegeterians

Why become a vegeterian?

Vegetarianism in India

In India vegetarian food is some times called as saivam food, satvic food, brahmin food and so on. The definition will widely vary.
Food and drink play a very important part in body and mind-control. Many sects and people have very crude ideas about food and drink. In ancient Indian medicine, garlic was a valuable remedy used as a tonic, roborans, to cure a lack of appetite, common weakness, cough, skin disease, rheumatism, haemorrhoids etc. In the Vedas – the garlic was mentioned among other medicinal plants. Onions is referenced in some of the oldest Vedic writings from India, China and Egypt. Medical treatise Charaka Sanhita celebrates the onion as a diuretic, good for digestion, the heart, the eyes, and the joints. Indian priests were the first physicians and pharmacists, who used items such as garlic.
A greater majority of Indians are non-vegetarians. The vegetarianism in India become popular after Buddhism and Jainism. Vedic literatures refer to Aryans as pastoral people, and they slaughtered cattle as food or beef-eaters. Indus Valley people were agriculturists. Emphasis on ahimsa, led to adoption of vegetarianism. For some Indians, their vegetarianism is itself their dharma. There are many communities living in the coastal stateswhere the consumption of meat or fish is very common. Early Indian kings and warriors who were expected to excel as hunters and warriors relied on a meaty diet. Manasollasa written during king Somesvara of the Western Chalukya Dynasty in the 12th century discusses many meat dishes. A suitable, healthy and hygienic diet included fatty pork fried with cardamoms and roast rump steak. With many types of vegetables, mutton, pork, sparrows and rats could all be found on sale in the markets of the Vijayanagara Empire. The Tantriks use fish, meat and wine freely in their worship.
Some Vishnu devotees do not eat onions and garlic and a lot of people use “vaishnav” to mean “vegetarian.” Some, didn’t personally like onions and garlic. Jains and some communities don’t use onions and garlic because they rip up the ground when they’re harvested. Onions and garlic are often used to flavor meat, so if someone was abstaining from meat they would give them up. Though Garlic and onion both have many health benefits, Jains have very strict dietary rules; Not only they are vegetarian, but some do not eat anything with seeds (this would prevent the plant from renewing its life) or any bulb for the same reason. Some do not eat plants that grow underground, including potatoes, because insects may be harmed in their harvest. Onions, ginger, or garlic, give off a strong odor and when a group monks meditate in forests or in a caves, it would produce a strong, pungent odor that would affect other people meditation.
Acceptance or prohibition of food has no relation to the taking of life, but categorized according to their supposed internal propensity to excite the passions. Gandhi attached great importance to diet, and argued vigorously that vegetarianism was more conducive to a life led according to the precepts of ahimsa. In this manner, as in many others, Gandhi had tapped on to beliefs widely shared in India.

Vegetarian Survival kit for Japan

(niku to sakana wa tabemasen) I don’t eat meat and fish.
(niku to sakana o tsukawanai ryouri o onegai dekimasu ka)
Could you make a meal without meat and fish?
Watashi wa vegetarian desu. = (I'm a vegetarian (see note below) )
Shojin ryori [show-zine ryo-ree] = (vegetarian cuisine, usually Buddist style)
Saishoku-shugi ryori wa arimasuka? = (Do you have any vegetarian meals?)
Shoujin ryori wa yatte imasuka? = (Do you serve vegetarian foods?)
Watashi wa ..(insert one of the following words here) o itadakimasen. (I don't eat ......)
doubutsu wa taberemasen (I can’t eat animals)
katsuo dashi mo taberemasen (I can’t eat fish stock)
doubutsu sei no mono wa subete taberemasen (I can’t eat any animal products)
wa taberemasen (I can’t eat _________) niku nashi (no meat)
Shojin ryori wa yatte imasuka? (Do you serve vegetarian foods?)
Thus "yasai dake o tabemas" means "I only eat vegetables"

"niku" = (nii-koo) (meat)
"sakana" = (sa-kah-nah) (fish)
"tori" = (tor-ri) (chicken (or any type of poultry) )
"tamago" = (tah-ma-go) (egg)
"gyunyu" = (giu-new) (milk)
"nyu seihin" = (new say-hinn) (dairy products)
"kani" = crab
"ebi "= shrimp
"kai" = shells
"ikka" = eel
"tako" = octopus
"buta" = pig (buta niku is pig+meat = {pork, bacon, ham,...}
"gyu" = cow (same pattern as above)
"hito" = humans
And while we're doing words:
"da-mei" = bad
"yasai" = vegetables
"dakei" = only
"tabemas" = I eat