The antonyms for the word "art vertical" can be a combination of words that convey the opposite of the meaning. The word "art" refers to something that requires skill and creativity, while the word "vertical" is related to the direction that is from top to bottom or up and down. Therefore, the antonyms for the word "art vertical" could be words such as "non-artistic horizontal," "plain flat," or "uncreative level." These terms suggest a lack of creativity and skill, and they do not express the same effect that might be expected from the original term.