The word "undeferential" means showing no respect or willingness to obey authority or rules. Synonyms for the word can include disrespectful, insolent, impolite, impudent, rude, disobedient, defiant, insubordinate, and rebellious. These words suggest a lack of deference to those in positions of power, and an unwillingness to show proper respect and adherence to rules and conventions. Using synonyms for "undeferential" can add nuance and variation to your writing, allowing you to express a range of attitudes and emotions towards authority figures and the status quo.