You don't need to apologize, it's fine. I am not sure how to communicate this effectively, but if you want to both hold on to the "prison abolition" framing (which is fine) but also be understood by laypeople, it would probably be helpful to your advocacy to lead with the fact that you are using that much more specialized definition of "prison" and that in terms they would use, you do still acknowledge the need for prisons but basically want to replace the whole justice and carceral system with one that still has prisons (by the common definition) but is radically oriented toward rehabilitation and humane treatment. I truly think you'll have an easier time discussing with people and get fewer attacks that feel like mischaracterization (some of which will remain because there are malicious actors, but some stemming just from communication issues).

And if not, that's fine, I'm mostly saying this because I misunderstood you at first and saw a few other people also misunderstand you, despite the fact that I think everyone involved basically agrees.