Negativize is a term that is not very commonly used in the English language. It means to make something negative or to focus on the negative aspect of something. However, there are many other words that can be used as synonyms for negativize. These words include 'pessimize', 'depress', 'discourage', 'dishearten', 'diminish', 'undermine', or 'weaken' among others. All of these words can have different shades of meaning and can be used in various contexts. It is always a good idea to choose the right synonym depending on the situation and the intended meaning of the sentence.