Definition of folio

• n. - A leaf of a book or manuscript.
• n. - A sheet of paper once folded.
• n. - A book made of sheets of paper each folded once (four pages to the sheet); hence, a book of the largest kind. See Note under Paper.
• n. - The page number. The even folios are on the left-hand pages and the odd folios on the right-hand.
• n. - A page of a book; (Bookkeeping) a page in an account book; sometimes, two opposite pages bearing the same serial number.
• n. - A leaf containing a certain number of words, hence, a certain number of words in a writing, as in England, in law proceedings 72, and in chancery, 90; in New York, 100 words.