A person who believes in or studies aeons; a specialist in aeonic or extremely long-term processes.
From aeonic + aeonist (blended term). This appears to be a rare or specialized coinage combining aeon terminology with agent suffix -ist.
This word is so obscure it's barely documented, but it represents a real scholarly type: someone obsessed with deep time. Think of the geologists who spend careers studying single layers of rock—true aeonicaeonists of history.
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