Not too happy with you using autism to call someone dumb, but I'll leave this up assuming it was just a one-off.
Definition of sash for Students. 1  1 : a frame for a pane of glass in a door or window. 2  2 : the movable part of a window.
Curtain or Drapery Header terms (tops): 1  Rod Pocket ... is a space or pocket sewn at the top of a curtain into which the curtain pole rod is inserted. 2  Pinch Pleat ... is a traditional drapery header and comes in many different styles such as Double pinched pleats, Pencil pleats, Goblet pleats, Box pleats, Butterfly pleats, Cartridge pleats ...