The phrase "most parliamentary" is often used to describe someone or something that adheres closely to the rules and traditions of parliamentary procedure. Synonyms for this phrase might include "most procedural," "most formal," or "most punctilious." Other possibilities might include "most regulatory," "most law-abiding," or "most by-the-book." Essentially, any word or phrase that suggests a strict adherence to rules and regulations could be considered a synonym for "most parliamentary." Whether you are describing a person, an organization, or a particular event, these synonyms can help you convey a sense of seriousness, decorum, and respect for established procedures and etiquette.