quesadilla UK /ˌkeɪ̯səˈdiː(l)jə/US /ˌkeɪ̯səˈdijə/ noun2 •A Mexican dish made by filling a tortilla with cheese and sometimes other ingredients and then cooking it until the cheese is melted. •A Salvadoran pan dulce made with rice flour and queso duro blanco and topped with sesame seeds.In the Salvadoran bakery, the quesadilla is king, whether cut into squares from a cake tray or baked into discus-sized round coffee cakes. — 2015 formsquesadillas