Catilinian is a term that is often used to describe something related to the infamous Roman politician, Catiline. However, there are several synonyms that can be used interchangeably with this word. These include terms like "treacherous," "deceitful," "dangerous," "untrustworthy," "disloyal," and "duplicitous." Each of these synonyms captures a different aspect of the character of Catiline and the deeds that he is famous for. So whether you are looking to describe a person, a situation, or a piece of literature, there are plenty of alternative words that you can use to convey the same meaning as "Catilinian".