quar·to noun \ˈkwȯr-(ˌ)tō\
: the size of a piece of paper cut four from a sheet; also : paper or a page of this size
: a book printed on quarto pages
Origin of QUARTO
Latin, abl. of quartus
First Known Use: 1589
Seen & Heard
What made you want to look up quarto? Please tell us where you read or heard it (including the quote, if possible).