Definition of octodecimo in English:

octodecimo

noun

  • 1A size of book page resulting from folding each printed sheet into eighteen leaves (36 pages).

    1. 1.1 A book of octodecimo size.
      • ‘Rawles describes an octodecimo printed by Wechel and owned by a Scot.’

Origin

Mid 19th century: from Latin in octodecimo in an eighteenth, from octodecimus eighteenth.

Pronunciation:

octodecimo

/ˌɒktəʊˈdɛsɪməʊ/