quar ‧ to /ˈkwɔːtəʊ $ ˈkwɔːrtoʊ/ BrE AmE noun ( plural quartos ) [countable] technical
[ Date: 1500-1600 ; Language: Latin ; Origin: quartus ; ⇨ ↑ quarter 1 ]
the size of paper made by folding a normal large sheet of paper twice to produce four sheets