What is vegetarianism?

Welcome to /vegetarian here on Digg. This is all going in the FAQ, but first I wanted to present this as a post so people can clarify what vegetarian is, as it means something different to many, even among vegetarians.

The most widely accepted definition of vegetarian in the western world is “Has absolutely no meat, animals, fish, or insects used in its cooking, whereas byproducts of these are acceptable.”

This also means no lard, no shrimp or anchovies put in sauces, no chicken or beef stock, and in most cases, no cross contamination (no using the same pot that had chicken to cook a vegetarian meal without cleaning it first). Commercial foods that include meat in “natural flavors” or chemicals that are animal-derived [gelatin] are also not vegetarian. Finally, cheese that makes use of animal rennet is technically not vegetarian, but many vegetarians are not that granular in their adherence to vegetarianism.

For many, especially in the western world, it is often hard to find a restaurant that adheres to this definition or even completely understands it, so cross contamination is especially prevalent.* In some cases, such as with sugar mentioned above, it is very regularly ignored as a convenience.

However, there are different types of vegetarian--

Some popular ones:

“Lacto-vegetarian”—Basically just means milk-vegetarian; a vegetarian that drinks milk, but unlike “lacto-ovo vegetarian” does not consume eggs.
Lacto-ovo vegetarian—what the western world calls vegetarian. Indian vegetarians refer to this sometimes as “eggetarian” to distinguish it from what is considered a standard vegetarian in India [“lacto-vegetarian”]
“Buddhist Vegetarian”—also sometimes called Chinese vegetarian, or Jain vegetarian [although these names are not exactly accurate], this type of vegetarian eats as a lacto-ovo vegetarian and also avoids garlic, leeks, alliums, and some herbs that are considered antagonistic to focusing on Buddhist practices. In Japan these meals are called “精進料理 (shōjin ryōri)”.

I'll put some more here in a bit. If you have anything to add please comment and I can add it to the FAQ.