The antonyms for the word "semicivilized" would be "uncivilized," "barbaric," or "primitive." These words describe societies or cultures that lack modern amenities, are not organized, or have lower levels of education and technology. In contrast to the term "semicivilized," which implies a society that is partially advanced or developed, these antonyms suggest a lack of progress or advancement. The term "uncivilized" implies a lack of manners, basic education, or decent living conditions, while "barbaric" suggests uncivilized behavior, cruel practices, or savage customs. Finally, "primitive" indicates a society that is simple, undeveloped, or traditional, often with limited or nonexistent technology.