[htfu]

Why would a Christian say a fetus is conscious? There's no such nonsense inherent in that faith.

I would extend your "some vegans" to "most everybody" - who seriously thinks complex animals are unconscious automatons? And how would that even work? Tiny few-celled organisms surely aren't and where exactly the line goes we don't know, and like you say it depends on how the word is defined and used, but isn't "stimuli causes not just reaction, but qualia" pretty standard?