The story
From demi- + -arian, modeled after vegetarian. Coined by the Nitrogen in Europe programme within the The Barsac Declaration, launched in November 2009.
First known use, by meaning
- from 2009 Of or relating to the type of diet in which meat consumption is reduced to half of what is culturally typical; of or relating to demitarianism.
Etymology from Wiktionary, CC BY-SA 4.0.