The phrase "most biggety" suggests arrogance, self-importance, or conceit. One synonym that captures a similar idea is "haughty," which connotes a disdainful attitude towards others. "Pompous" also comes to mind, as it describes an individual who thinks highly of themselves and is often pretentious. "Egotistical" could be another synonym to describe someone who is exceedingly self-centered, while "arrogant" encompasses both a sense of superiority and a lack of humility. "Conceited" is yet another synonym that describes someone who is excessively proud and self-absorbed. In sum, various synonyms for "most biggety" convey the same or similar shades of meaning, pointing to an inflated sense of self-worth.