The term 'THUMBED (THROUGH), AS A BOOK' can be summarized as the act of flipping through a book by using one's thumb to quickly scan the pages. This is a common practice for people who are looking for a specific piece of information or trying to get a general overview of the contents of a book. The crossword solution for this term is 'LEAFED, ' which is another way of saying that someone has gone through the pages of a book.