While watching Master and Commander: Far Side of the World over the weekend, Sarah and I started talking about the origin of the word vegetarian.
In the movie, which is set in 1805, a character describes lizards that live on the Galapagos as 'vegetarians.' This immediately set my nerves jangling as the idea of people being vegetarian in 1805 just didn't sound plausible. Some research uncovered the fact that the word vegetarian wasn't used/coined until 1842. So, the anachronistic color of the word in that setting was true. Sarah and I tossed around the idea that in 1805, animals that only ate plants would mostly have been described as 'herbivores,' especially by scientists of the day (as the character in question was).
That got us wondering if someone could be an herbivorian. If a vegetarian eats vegetables, wouldn't an herbivorian eat herbivores? That is, would your diet be limited to cows, goats, pigs, chickens, and other animals that eat plants?
Of course, the problem is that we took our cue from the word vegetarian. If the suffix -ian meant "consumer of," then Christians would literally eat Christ (and depending on your religion, this may actually be the case). However, the suffix -ian means "follower of" or "of or belonging to." So, an herbivorian would actually literally mean "someone who follows the way of herbivores" or "belonging to the category of herbivores".
Given that, vegetarian is actually an incredibly incorrect word construction (all hail English!). Those who practice vegetarianism then literally "belong to the category of vegetables."