The Collaborative International Dictionary of English v.0.48:

Yunca \Yun"ca\ (y[=oo][ng]"k[.a]), n.
   An Indian of a linguistic stock of tribes of the Peruvian
   coast who had a developed agricultural civilization at the
   advent of the Spaniards, before which they had been conquered
   by the Incas. They constructed irrigation canals which are
   still in use, adorned their buildings with bas-reliefs and
   frescoes, and were skilled goldsmiths and silversmiths. --
   Yun"can, a.