I'm not sure what we're disagreeing over.
Here we go:
Dictionaries are compiled by lexicographers to document the usage of terms. If a common usage is not in a dictionary, it means the lexicographers missed it or deliberately excluded it.
If you did some research on eugenics, instead of looking it up in a dictionary, you'd be more informed about what is relevant to the topic.
Contrary to what many neurodiverse people think, language is not something you get to redefine as it suits your worldview. I say "neurodiverse people" because I've spotted a few aspies and auties who like to redefine language based on their personal agenda. Go to chatautism, sometime. You'll find one guy named "beware" who does it nonstop. (He is otherwise fluent in english)