octavo

 
Pronunciation: /ɒkˈtɑːvəʊ, -ˈteɪ-/
(abbreviation: 8vo)

noun (plural octavos)

  • a size of book page that results from folding each printed sheet into eight leaves (sixteen pages): foolscap octavo three octavo volumes
  • a book of octavo size.

Origin:

late 16th century: from Latin in octavo 'in an eighth', from octavus 'eighth'