The antonyms for the phrase "more overnice" are many, as it refers to a level of excessive niceness or fastidiousness. Some possible antonyms include rude, impolite, unkind, offensive, disrespectful, insensitive, insensitive, unpleasant, uncouth, and uncivil. Essentially, any words that describe behavior or attitude that are not overly nice or polite would be the opposite of "more overnice." It is important to note that being "overly nice" can sometimes be seen as insincere, and it is important to find a balance between being polite and genuine in our interactions with others.