n (context|books) A book made of sheets of paper each folded once (two leaf | leaves or four pages to the sheet); hence, a book of the largest kind, exceeding 30 cm in height.
n (context|printing) 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.
n (accounting) a page in an account book; sometimes, two opposite pages bearing the same serial number.
n (legal|dated|19th century|early|20th century) 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.