bookworm; bibliomaniac; book nut
Derogatory term for someone obsessed with books, often implying excessive or eccentric devotion to reading or collecting.
He's a bookworm who reads all day long.
That bibliomaniac's room is filled with books.
Compound of 書 (sho, 'book') and 痴 (chi, 'fool' or 'obsession'), literally 'book fool'. The exact historical derivation is uncertain, but the kanji combination conveys the derogatory sense of someone foolishly obsessed with books.