conjunction/ˈdeske/
since, after; as, seeing that
“[…], y si el árbol es delicado, y se temen que por ser chico al invierno se le ha de elar, puédele sembrar en tiesto, y desque esté grande trasponerle en tierra.” — […] , and if the tree is delicate, and it is feared that due to being small the winter may freeze it, you may plant it in a pot, and after it grows big transplant it into the ground.
Inherited from Old Spanish desque, from des + que, from Late Latin dē ex and Latin quid respectively. Became rare and non-standard by the 18th century, displaced by después de que, desde que, ya que.