Except for some isolated restaurant-related insertions, I’ve tried to avoid eating animals (marine or land) for 20 years. Except for the inevitable beetle carapaces and various arthropod parts so popular in food colourings. My personal definition of “animals” is functional/phylogenetic, based on their being eukaryotic heterotrophic Opisthokonts and specifically multicellular, which conveniently excludes most protists, yeasts, algae (seaweed), plants, and so on.
This is usually too difficult to explain to servers in restaurants, so I usually say “no flesh, no fish, no birds”. I used to just say “no meat” until I realised that people have a hazy and culturally contingent definition of what “meat” means.
But the dilution of the word “vegetarian” has reached such a point where I usually don’t say I am one, and have managed to more or less remember not to use that label to identify myself. It’s sad when a word like vegetarian now requires so many adjectives and qualifiers to pin down its meaning. The utility of labelling and stereotypes is that they should be quick cognitive shortcuts that avoid having to engage much thought.
I’ve also been trapped at parties by born-again self-identified “vegetarians” or “ex-vegetarians” who sometimes take an inappropriate amount of time telling me why they eat or do not eat things. It often puzzles me why people are so intense on this subject, until I remember my Barthes.
To impose your own dietary preferences on others is a slippery slope. Your begin with reasonableness, pass through invective, and end up with sacred/profane structures of taboo, hala, and kashrut.