sexto
(ˈsɛkstəʊ)
[a. L. sextō, ablative case of sextus sixth: cf. quarto, etc.]
The designation of the size of a book, or of the page of a book, in which each leaf is one-sixth of a sheet.
| 1847 De Morgan Arithm. Bks. Introd. 11 When he folds a sheet of paper into six leaves, making what ought to be a sexto book, he calls it a duodecimo printed in half sheets. |