duodecimo

 
Pronunciation: /ˌdjuːə(ʊ)ˈdɛsɪməʊ/

noun (plural duodecimos)

  • a size of book in which each leaf is one twelfth of the size of the printing sheet.
  • a duodecimo book.

Origin:

mid 17th century: from Latin (in) duodecimo 'in a twelfth', from duodecimus 'twelfth'