If you have encyclopedic knowledge of a subject, you know a huge amount about it — almost as if a whole reference book lives in your head. People mostly use this of knowledge, memory, or a mind: encyclopedic knowledge of jazz, of birds, of old film.

If you have encyclopedic knowledge of a subject如果你對某個主題有encyclopedic knowledge，you know a huge amount about it你懂得非常多——almost as if a whole reference book lives in your head幾乎就像有一整本參考書活在你腦子裡。People mostly use this of knowledge, memory, or a mind人們大多用它來形容知識、記憶或頭腦：encyclopedic knowledge of jazz, of birds, of old film像是對爵士樂、鳥類、老電影的百科全書式知識。

It is a complimentary, slightly bookish word. You will meet it in writing and from teachers more than in quick chat.

It is a complimentary, slightly bookish word這是一個帶稱讚意味、有點書卷氣的字。You will meet it in writing and from teachers more than in quick chat你會在寫作和老師口中遇到它，比在隨口聊天裡多。

Though actually, it does not mean you know everything in the world; it means that one field is unusually wide and full in your head.

Though actually不過事實上，it does not mean you know everything in the world它不是說你什麼都懂；it means that one field is unusually wide and full in your head而是說某一個領域在你腦子裡特別寬廣、特別完整。

There is a quieter second use, too: an encyclopedic book or article tries to cover a subject from end to end, like a true reference work. It is not a word for “smart in general.” Someone can be clever and still not have encyclopedic knowledge of anything.

There is a quieter second use, too還有一個比較少人注意的第二種用法：an encyclopedic book or article tries to cover a subject from end to end一本或一篇encyclopedic的書或文章試著把一個主題從頭寫到尾，like a true reference work就像一本真正的參考書。It is not a word for "smart in general."它不是用來說「整體上很聰明」的字。Someone can be clever and still not have encyclopedic knowledge of anything一個人可以很聰明，卻對任何領域都沒有百科全書式的知識。