Translation guide
A person who knows a great deal of factual information, especially vocabulary or trivia.
To describe someone who has an extensive vocabulary or encyclopedic knowledge.
Literally 'living dictionary'. The most direct and natural equivalent for a person who knows many words or facts. Often used with a sense of admiration.
He's a walking dictionary.
A knowledgeable person; a general term for someone who knows a lot. Less specific than 'walking dictionary' but very common.
Extensive knowledge; erudition. More formal and often used as a noun or adjective rather than a direct label for a person.
That teacher is like a walking dictionary.
He really is a walking dictionary, isn't he?
彼の博識には驚かされる。
I'm amazed by his encyclopedic knowledge.