something which is obscenely cruel; primitive; unsophisticated
Barbarian originates from the Greek word bárbaros meaning "babbler", to denote the "unintelligible sounds" ("bar bar bar") made by foreign speakers. Similar words exist in many other languages, for the identical purpose labeling a "strange"/"foreign" person/culture.
In modern day usage, you can notice this rhetoric being employed almost always for the purpose of demonizing "foreign" (more often than not from the global south) cultures - cultures that need to be civilized; cultures that need to be colonized to rescue them from themselves. A perfect lingual weapon for warmongers and racists alike. Equally repulsive sibling of "savage".
When you use words, that are in vogue primarily inside circles of bigots, with racist etymologies, it's a wilful act of violence, ignorance and an indication to the vilified and minoritised communities that their history of wounds and abuses are inconsequential to our words.
Avoid words that have obscene etymologies. There is almost always a better alternative: an inclusive and a less hurtful one.