Main Entry: quar·to

Pronunciation: \ˈkwȯr-(ˌ)tō\

Function: noun

Inflected Form(s): plural quartos

Etymology: Latin, abl. of quartus fourth

Date: 1589

1 : the size of a piece of paper cut four from a sheet; also : paper or a page of this size
2 : a book printed on quarto pages