More plumbean is an unusual phrase, and it might be difficult to come up with synonyms for it. However, it can be interpreted as meaning "more strange" or "more eccentric." In that case, some synonyms for more plumbean could include bizarre, quirky, unconventional, odd, offbeat, peculiar, or outlandish. These words all describe something that is outside of the norm or expected, making them an apt replacement for more plumbean. Additionally, synonyms for more plumbean could include words that describe someone as being more aloof or introverted, such as brooding, introspective, or distant.