Describes a person or their remarks as having broad or deep knowledge. Often used in formal or written contexts.
He is very knowledgeable about history.
She gave us a well-informed opinion.
博識 is a noun meaning 'extensive knowledge' or 'erudition', often used for scholarly breadth. 知識豊富 is more descriptive and can be used as a na-adjective to describe a person or their remarks.
Compound of 知識 (knowledge) and 豊富 (abundant). The exact historical derivation is uncertain, but the meaning is transparent from its components.