Size of book (5)

I believe the answer is:

folio

(Other definitions for folio that I've seen before include "Book; wrapper for loose papers" , "Folded sheet - or book made from such" , "File" , "Four pages" , "Two-leaf sheet" .)

I've seen this clue in The Times and The Guardian.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.