Most pissed is a term commonly used to express extreme anger or frustration. However, there are many other words and phrases that can be used as synonyms for this expression. Some examples include: infuriated, livid, enraged, seething, fuming, boiling, irate, incensed, and wrathful. Each of these words has a slightly different connotation and can be used to describe various degrees of anger. Ultimately, the choice of which synonym to use comes down to personal preference and the specific context in which the emotion is being expressed. Regardless of the word chosen, it's clear that extreme anger is being conveyed.