There are a few different definitions of veganism, the word itself isn't very old and has often been used to describe not just the a plant-based diet, or abstaining from all animal products, but the philosophy behind it.
This is one of the reasons why currently "plant-based diet" is gaining traction, to take the emphasis off the word vegan because it's been connected to the animal rights and ethics of the vegan movement. [1]
> " I taught cooking classes for the national non-profit, Physicians Committee for Responsible Medicine, and during that time, the phrase "plant-based diet" came to be used as a euphemism for vegan eating, or "the 'v' word." It was developed to take the emphasis off the word vegan, because some associated it with being too extreme a position, sometimes based exclusively in animal rights versus a health rationale."
This is one of the reasons why currently "plant-based diet" is gaining traction, to take the emphasis off the word vegan because it's been connected to the animal rights and ethics of the vegan movement. [1]
[1] https://web.archive.org/web/20150611163242/http://www.tampab...
> " I taught cooking classes for the national non-profit, Physicians Committee for Responsible Medicine, and during that time, the phrase "plant-based diet" came to be used as a euphemism for vegan eating, or "the 'v' word." It was developed to take the emphasis off the word vegan, because some associated it with being too extreme a position, sometimes based exclusively in animal rights versus a health rationale."