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.
The plastic and metal assembly on which the cam pivots of a double hung or single hung sash rest. The clutch is attached to the block and tackle system of the balance tubes which allow opening and closing of the sash. The clutches are color coded for easy identification of balance strength. Combination Door.