An antonym for the Spanish word, Culto is Ignorante or inculto.
What is the word, culto?
"Culto" refers to someone who has a good education and knowledge of art, literature, and other cultural matters. It can also describe something refined and sophisticated.
Some antonyms for the word are Ignorante, inculto, salvaje and palurdo. Note that antonyms are words that are opposite in meaning to a given word.
We can form a sentence with the word as follows; "El doctor es un hombre muy culto y educado" and this means that "The doctor is a very cultured and educated man."