a leaf of a book or manuscript.-a sheet of paper once folded.-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.-the page number. the even folios are on the left-hand pages and the odd folios on the right-hand.-a page of a book; (bookkeeping) a page in an account book; sometimes, two opposite pages bearing the same serial number.-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.