There's no reason for them to be absolute, is there? If I eat one non-vegan meal every 20 meals, then I think it's reasonable to say my diet is 95% vegan.
> If I drink only at weekends, am I a semi-teetotaller? That's ridiculous.
I've been tee-total for over 10 years. I've sipped someones drink a handful of times to see what it tasted like, can I not say I was tee-total anymore?
The definitions are more about proclamations. If today I decide to be a vegan, then tomorrow I will call myself a vegan despite having only abstained for 24 hours so far. If I decide to eat meat a couple times a month then I'll tell people I'm predominantly vegan, they understand what I mean.
Definitions of social things are never that rigid. Was my grandmother a teetotaler? The only alcohol she ever consumed for the last 70 years of her life was a tiny bit of wine during communion every few weeks.
These definitions are rigid. Anyone can do something they are not supposed to once in a while but 'vegan' and 'vegetarian' do mean that you refuse to eat animal products or meat, not that you don't eat much of them.
> Anyone can do something they are not supposed to
What do you mean not supposed to? My grandmother wasn't supposed to drink? Her being a teetotaler was just the result of her daily choices. That's what eating vegan meals is for me.
Do you have to explicitly choose to be a vegan? If prisoners were fed 100% vegan diets and had no options for outside foods, would they be vegans? I guess I'm wondering if intent matters just as much as action, or is one or the other good enough?