A person who follows the diet and/or lifestyle that promotes not using any animal products or byproducts.
The vegan diet and lifestyle are both impossible to follow to the fullest, so most vegans tend to stop when it becomes inconvenient
. For example, animal products are used to vulcanize
rubber and process steel. So a true vegan would be forced to shun most anything found in an industrialized nation, notably things such as cars, buses, airplanes and bicycles. Also, the vegan diet does not and cannot supply vitamin B12, as this essential vitamin only comes from meat and dairy. So a vegan must either take vitamin supplements, (which one way or another come from an animal) give up the diet altogether, or face B12 deficiency; which can cause brain damage.
Generally, vegans tend to ignore such glaring contractions and problems, preaching that they are the moral elite; even if they happen to be wearing leather shoes.