It occurred to me recently that in my personal case, one such example is eugenics. I first came across that word as a schoolboy reading some nonfiction on biology (I forgot which) by Peter Medawar. Perhaps the only thing that I remember from that book (I was, as I still am, a lazy reader) was how it puzzled me (as many translated books tend to do) with a passing mention of eugenics, and how the point that the author was making "of course was not eugenics", or some such. There might have even been editor’s footnote explaining the term eugenics, from which it was not obvious why the author made an effort to distance the discussed topic from that idea. Medawar, I think, expected his readers to have an instant, conditioned negative response to the word (because Nazis etc.). I had not been conditioned to have it.
I think there is still a menacing undertone to the word eugenics; and yet, in the vision of many, perhaps at present most vocally — Harari, humans will inevitably start to biologically improve their species, which is essentially what the idea of eugenics was all about.
