There are plenty of synonyms for the phrase "most barbarity". Some of the most common ones include "cruelty," "brutality," "savagery," "barbarism," "violence," and "inhumanity." Each of these words conveys a sense of extreme cruelty or brutality towards others, often characterized by a lack of empathy or compassion. While "most barbarity" may be used in a variety of contexts, such as describing the actions of a dictator or the horrors of war, its synonyms can be used to describe any situation where extreme cruelty is present. No matter the word chosen, the meaning is always clear: the actions being described are among the most inhumane and brutal that can be imagined.