windowpane

noun3

1. •
   A piece of glass filling a window or a section of a window.
2. •
   A fabric pattern of widely-spaced intersecting vertical and horizontal lines forming large squares.
3. •
   (slang) A gelatin base tab with LSD.

   • Another form is called a windowpane. Windowpanes are small thin squares of gelatin treated with LSD that look like little pieces of plastic. — 2004