folio
1. fo.lio \'fo--le--.o-\ n [ME, fr. L, abl. of folium] 1a: a leaf esp. of a
manuscript or book 1b: a leaf number 1c: a page number 1d: an
identifying reference in accounting used in posting 2a: a sheet of paper
folded once 2b: a case or folder for loose papers 3a: the size of a piece
of paper cut two from a sheet; also : paper or a page of this size 3b: a
book printed on folio pages 3c: a book of the largest size 4: a certain
number of words taken as a unit or division in a document for purposes of
measurement or reference
2. folio vt : to put a serial number on each leaf or page of