In your analogy of books, google is a book too. If google as a book dictionary was just a copy of your book dictionary, that would be illegal and wrong. You the

In your analogy of books, google is a book too. If google as a book dictionary was just a copy of your book dictionary, that would be illegal and wrong. You the reader are only looking at a single definition, which could be a plausible fair-use quote. But when google's entire dictionary is just fair-use quotes of your book, then they've just copied your book.