have (one's) nose in a book
To be reading a book. Often used of people who always seem to be reading. He's had his nose in a book for the entire camping trip. I wish he would take a break and enjoy the scenery. Poor Mary is so shy. She just has her nose in a book wherever she goes.
nose in a book, have one's
Be constantly reading, as in Walter is known for having his nose in a book. This expression graphically depicts immersing oneself in reading. [Mid-1900s]