the.com/abolitionist

means Someone who actively campaigned to end slavery and have it outlawed, rather than merely disapproving of it in private.

from Built from 'abolish' (to do away with entirely), which traces back through French to Latin 'abolere,' meaning to destroy or abolish — itself possibly linked to 'olere,' to grow. 'Abolitionist' took on its specific, charged meaning in the late 1700s and 1800s, when it came to name those organizing specifically against slavery — first the transatlantic slave trade, then slavery itself — rather than any general reformer. The word carries its history: it was a movement name before it was a dictionary entry.